Finance calculators that show the steps
- Calculators
- 132
- Guides
- 216
- Worked examples
- 1,307
- Tools you can drag
- 67
A $2,000 weekly check with 12 percent federal withholding leaves $1,607. FICA is $153. Each calculator below runs in the browser, shows the formula it used, and works a real example in numbers.
Start with a number that is already checked
- Paycheck and FICA$1,607 take-home
- Loan payment$1,580.17 a month
- Compound interest$41,872.85
- Mortgage affordability$430,333.43
- APR against APY5.116%
- Net present value$1,978.13
- CAGR10.29%
- Leverage ratios1.67 / 62.50% / 2.67
- Net worth$100,000
- Price to earnings20.0x
- Enterprise value$130,000,000
- Discounted cash flow$1,292,720.05
- Required minimum distribution$20,000
- Social Security PIA$2,345.80
- FDIC insurance$250,000 covered
- HELOC interest only$333.33 a month
- Sharpe ratio0.8
- CAPM required return11.2%
- Cash-on-cash return2.45%
- Mortgage escrow$650 a month
- I bond composite4.218%
- Tax brackets$8,160
- Claiming age$1,642.06
Put a calculator on a class page from widgets, starting with the paycheck widget. For the draggable pictures, use embed graphs.
Class and first paycheck
Simple interest calculator and formula
Simple interest is principal times rate times years. It adds the same amount every year. Work a savings balance or a loan, then see why compounding is a different rule.
Hourly wage to annual salary
Turn an hourly wage into weekly and annual pay. Hours a week and weeks a year are inputs, so a part-time job and unpaid time off both show up. Educational, not a tax engine.
Paycheck calculator and FICA split
See where a paycheck goes: Social Security, Medicare, and the withholding you type. FICA is the part the formula actually fixes. Educational, not a tax engine.
50/30/20 budget split calculator
The 50/30/20 rule splits take-home pay into needs, wants and saving. Type the leftover and see the three buckets, including when housing already breaks the 50.
Net worth calculator and formula
Net worth is what you own minus what you owe, on one date. Work a household sheet, then see why two families with the same figure can sit in very different positions.
Credit utilization calculator
Credit utilisation is the reported revolving balance divided by the revolving limit. Work the ratio, the headroom, and why paying in full may still show a balance.
Emergency fund calculator: size and time
Size an emergency fund from your own essential monthly costs, then work out the deposit and how long the fund takes to build at a rate you pick.
FDIC insurance calculator
FDIC coverage for one depositor, one insured bank and one ownership category is the smaller of the balance and the limit. Run the identity on two balances.
Saving and growth
Compound interest calculator and formula
Work out what savings grow to with compound interest. Shows the formula, a worked example with monthly deposits, and why compounding frequency changes the total.
Savings goal calculator: monthly deposit
Work out what to put away each month to hit a target by a deadline. Shows the formula, three worked examples, and why money you already have cuts the deposit.
Rule of 72 calculator and doubling time
Divide 72 by the annual growth rate to see how long money takes to double. Shows the exact answer beside the estimate, and the rates where the shortcut drifts.
Inflation calculator and buying power
Work out what a sum will cost after years of inflation, what today's money will buy by then, and how much buying power a modest rate takes over a working life.
Real return after inflation calculator
Work out what a return is worth once inflation is taken out. Shows the Fisher relation, three worked examples, and why subtracting inflation gives the wrong answer.
Future value of an annuity calculator
Work out what a run of level payments grows to. Shows the annuity formula, worked examples paid at the end and at the start of each period, and what timing changes.
Present value calculator
Discount a future lump, a level payment stream, or both, at a stated rate and compounding frequency. The ordinary-annuity convention used here matches a bond coupon or a rent paid at period end.
CAGR calculator and formula
Work out a compound annual growth rate from a start value, an end value and a number of years. Shows the formula, worked examples, and why averaging yearly returns overstates growth.
APR vs APY calculator and formula
Convert between APR and APY, and see what compounding frequency does to a rate. Shows the formula, worked examples for savings and for a credit card.
CD interest calculator
A certificate of deposit grows by its APY once a year. \$10,000 at 4.50 percent for 5 years becomes \$12,461.82, which is \$2,461.82 of interest.
Savings rate calculator
A savings rate is what you save over what you earn. \$15,000 out of \$75,000 is 20 percent, and \$24,000 out of \$80,000 is 30 percent.
Coast FIRE calculator
Coast FIRE asks whether what you hold will grow into your number alone. \$200,000 at 7 percent for 20 years reaches \$773,936.89 against a \$1,000,000 target.
Borrowing
Loan payment calculator and formula
Work out the monthly payment on a mortgage or loan, what it costs in total interest, and how each payment splits between interest and principal.
Mortgage affordability calculator and formula
Work out the largest mortgage a debt-to-income rule allows, the price it buys once your deposit is added, and how far that ceiling falls when the rate rises a percentage point.
Mortgage extra payment calculator
What an extra amount paid each month does to a mortgage: months taken off the term, interest not paid, and the point where extra principal stops covering that month's interest.
Credit card payoff calculator and formula
Work out how many months a card balance takes to clear at a fixed monthly payment, what the interest adds up to, and how much of the first payment is interest.
Car loan calculator: payment and total cost
Work out the monthly payment on a car loan, the interest it costs in total, and how a longer term lowers the payment while raising what you hand over.
Student loan payoff calculator
Work out the payment that clears a student loan over its standard term, what the interest costs in total, and how many months an extra fixed amount takes off.
Debt-to-income ratio calculator and formula
Work out your DTI from monthly debt payments and gross income. Shows the formula, front-end against back-end, and the room left under a lender limit.
Refinance break-even calculator and formula
Work out how many months of lower payments it takes to earn back the closing costs on a refinance, and whether the new loan costs more interest over its life.
PMI calculator and formula
Private mortgage insurance as a percent of the original loan, paid monthly until the amortised balance falls to 80 percent of the original purchase price.
Mortgage points calculator
What discount points cost in cash, how much they cut the monthly payment, and how many months of that saving it takes to recover the points if you keep the loan.
HELOC interest-only calculator
A HELOC interest-only charge is the drawn balance times the annual rate, divided by 12. Run that identity, then see why repayment is a different payment.
Escrow calculator and formula
Mortgage escrow is annual tax plus insurance, divided by twelve. On \$6,000 of tax and \$1,800 of insurance the base deposit is \$650 a month.
Gift tax exclusion calculator
Gift tax exclusion room is the cap minus the gift. This calculator shows a \$4,000 gift against a \$19,000 annual cap leaves \$15,000.
Margin buying power calculator
Margin buying power is cash divided by initial margin. This calculator turns \$10,000 at 50 percent margin into \$20,000 of buying power.
PITI mortgage payment calculator
PITI is principal, interest, taxes and insurance in one figure. A \$250,000 loan at 6.5 percent plus \$500 tax and \$150 insurance is \$2,230.17 a month.
Loan to value calculator
Loan to value is the loan over the property value. A \$320,000 loan on a \$400,000 home is 80 percent LTV with \$80,000 of equity.
Biweekly mortgage calculator
Half a mortgage payment every two weeks makes 26 half payments a year. On \$250,000 at 6.5 percent that clears in 628 periods and saves \$73,434.82.
Interest only mortgage calculator
An interest only payment is balance times rate over 12. \$400,000 at 6.5 percent costs \$2,166.67 a month and \$26,000 a year, with nothing off the balance.
Remaining loan balance calculator
After 60 payments a \$250,000 loan at 6.5 percent still owes \$234,027.44. Wait until 120 payments and the balance is \$211,940.32.
Years to payoff calculator
\$400 a month clears a \$12,000 balance at 21.99 percent in 44 months. Total paid is \$17,577.09, of which \$5,577.09 is interest.
Down payment calculator
A down payment is price times percent, and the loan is the rest. 20 percent of \$400,000 is \$80,000 down and a \$320,000 loan to arrange.
Car lease payment calculator
A lease payment is depreciation plus a rent charge. \$30,000 down to an \$18,000 residual over 36 months is \$333.33 plus \$60, so \$393.33 a month.
Money factor calculator
A money factor is a lease rate in disguise. Divide the APR by 2400: 3 percent becomes 0.00125 and 6 percent becomes 0.0025. Multiply by 2400 to read it back.
Work and retirement
Employer match calculator
How a 50 percent match on the first 6 percent of pay actually works, what is left on the table if you defer less, and what the match stream grows to if it is invested.
Retirement withdrawal calculator and formula
Work out how long a pot lasts at a fixed monthly withdrawal and a steady return, what is left after twenty years, and what a lower return takes off the end.
FIRE number calculator
The pile that covers a year's spending at a stated withdrawal rate, and how many years of saving at a constant return it takes to reach it from what you have now.
RMD calculator and formula
A required minimum distribution is the prior year-end balance divided by an IRS life-expectancy factor. Run the identity, then see two checked examples.
Social Security PIA calculator
Social Security turns average indexed monthly earnings into a primary insurance amount with two bend points. Run the 90, 32 and 15 percent slices.
Social Security claiming calculator
Claiming age multiplies PIA. Sixty months early is a 0.70 factor. On a teaching PIA of \$2,345.80 that pays \$1,642.06 a month.
Taxable Social Security calculator
Provisional income adds half of benefits to other income. \$20,000 plus half of \$18,000 is \$29,000, which is \$4,000 over a \$25,000 base, so \$2,000 is taxable.
Life insurance needs calculator
A cover need is income to replace plus debts, less assets and cover in place. \$80,000 for 10 years plus \$200,000 of debt nets out at \$850,000.
Roth conversion tax calculator
Roth conversion tax is converted value times an entered rate. This calculator applies 22 percent to \$20,000 and returns \$4,400.
Effective tax rate calculator
Effective tax rate is total tax divided by income. This calculator divides \$8,160 by \$60,000 and returns an effective rate of 13.6 percent.
Tax bracket calculator
A tax bracket calculation stacks income through band rates. This teaching calculator puts \$60,000 through three bands and returns \$8,160.
Self-employment tax calculator
Self employment tax uses 92.35 percent of net earnings, then a 15.3 percent rate. This calculator turns \$80,000 into \$11,303.64.
QBI deduction calculator
QBI deduction in this uncapped case is qualified business income times 20 percent. This calculator turns \$80,000 into \$16,000.
NIIT calculator and formula
NIIT on a supplied investment income slice is that slice times 3.8 percent. This NIIT calculator turns \$20,000 into \$760 of tax.
Tax-loss harvest calculator
Tax loss value is realised loss times an entered tax rate. This harvest calculator finds a \$4,000 loss and \$880 at a 22 percent rate.
Capital gains tax calculator
Capital gains tax falls on the gain, not the sale price. Selling for \$40,000 what cost \$25,000 is a \$15,000 gain, and 15 percent of it is \$2,250.
Home sale exclusion calculator
The exclusion applies to the gain. A \$520,000 sale on a \$200,000 basis is a \$320,000 gain, and a \$250,000 exclusion leaves \$70,000 taxable.
After tax return calculator
An after tax return is the nominal return times one minus the tax rate. An 8 percent return taxed at 22 percent leaves 6.24 percent, a drag of 1.76 points.
Additional Medicare tax calculator
The additional Medicare tax is 0.9 percent of wages above a threshold. \$250,000 against a \$200,000 threshold gives \$50,000 of excess and \$450 of tax.
Investing and valuation
Price to earnings calculator
P/E is share price divided by earnings per share. Work the ratio, then the same number from market cap over total earnings. A low P/E is not always cheap.
DCF calculator and formula
Two-stage discounted cash flow: present value of an explicit forecast plus a Gordon-growth terminal value. Terminal growth has to stay below the discount rate or the perpetuity has no finite value.
Dividend discount calculator
Gordon growth prices a stock as next year's dividend over required return minus perpetual growth. The implied yield equals that gap, and growth has to stay below the required return.
Bond price calculator and current yield
Price a bond from its coupon rate, the market rate and the years to maturity, then see the current yield and why higher rates push the price below face value.
Bond duration calculator
Macaulay duration is the present-value-weighted wait for a bond's cash flows. Modified duration and DV01 then say how far the price moves when the yield moves.
Cap rate calculator
Capitalisation rate is net operating income divided by purchase price. The same income at a comparison cap gives the implied value, which is what makes two properties comparable.
Tax-equivalent yield calculator
The taxable yield that leaves the same after-tax amount as a municipal or other tax-exempt yield, at a stated federal marginal rate. State tax is a separate adjustment.
Expense ratio calculator and fee impact
Work out what a fund fee costs over time. The expense ratio comes off the rate your money compounds at, so a fraction of a percent a year adds up.
PEG ratio calculator and formula
Work out PEG from a price, earnings per share and an expected growth rate. Shows the P/E it is built on and what the ratio does as growth changes.
Price to book calculator
Work out price to book from a share price and book value per share, or from market cap and book equity. Shows both routes and where they disagree.
Price to sales calculator
P/S is price over sales per share, which is market cap over sales. A \$50 share on \$25 of sales is 2 times on \$5,000,000,000 of market cap and \$2,500,000,000 of sales.
Total return calculator
Total return is price change plus income, over the start. A holding bought at \$100, worth \$105, that paid \$3 returned 8 percent, not 5 percent.
Sharpe ratio calculator
The Sharpe ratio is excess return over volatility. Subtract the matching risk-free rate from the portfolio return, then divide by the same-scale standard deviation.
CAPM calculator and formula
CAPM required return is the risk-free rate plus beta times the market premium. Subtract the risk-free rate from the market return, scale by beta, then add the base.
Cash-on-cash return calculator
Annual leftover cash over the equity cheque is cash-on-cash return. Run the quotient on two checked pairs, then see why cap rate and IRR are different objects.
I bond composite rate calculator
A Series I bond composite rate is the fixed rate plus twice semiannual inflation plus their product. 1.2 percent fixed and 1.5 percent inflation produce 4.218 percent.
TIPS calculator and formula
TIPS principal follows inflation. This TIPS calculator turns \$1,000 at 2 percent for 3 years into \$1,061.21, with a \$10.61 coupon.
Treasury bill price calculator
Treasury bill price subtracts a bank discount from face value. This calculator prices \$10,000 at 5 percent for 180 days at \$9,750.
Call option payoff calculator
Call option profit is intrinsic value minus premium. At \$60 spot, \$55 strike and \$2 premium, this call payoff calculator returns \$3.
Put option payoff calculator
Put option profit is intrinsic value minus premium. At \$40 spot, \$45 strike and \$1.50 premium, this put payoff calculator returns \$3.50.
Stock split calculator
A stock split changes shares and price inversely. This stock split calculator turns 100 shares at \$80 into 200 at \$40, keeping value at \$8,000.
NAV per share calculator
NAV per share is assets minus liabilities, divided by shares. This NAV calculator turns \$500,000,000 less \$2,000,000 into \$49.80 per share.
ETF premium calculator
ETF premium compares market price with NAV. This ETF premium calculator finds a \$0.50 gap on \$49.80 NAV, equal to a 1.004 percent premium.
Rental cash flow calculator
Rental cash flow is effective rent less expenses and debt service. This calculator starts at \$2,400 monthly rent and returns \$1,960 a year.
Gross rent multiplier calculator
Gross rent multiplier is property price divided by annual gross rent. This GRM calculator divides \$360,000 by \$36,000 and returns 10.
DSCR calculator
Debt service coverage is NOI over annual debt service. \$36,000 of NOI against \$24,000 of payments is a DSCR of 1.5, and \$48,000 over \$40,000 is 1.2.
Net operating income calculator
Net operating income is rent minus vacancy minus operating costs. \$48,000 of rent, \$2,400 of vacancy and \$9,600 of costs leaves \$36,000 of NOI.
One percent rule calculator
The one percent rule tests monthly rent against price. \$2,400 a month on a \$240,000 house is exactly 1 percent, while \$1,800 is 0.75 percent.
Yield to maturity calculator
Yield to maturity is the rate that prices a bond. A \$1,000 face bond with a 5 percent coupon, 10 years left and a \$857.88 price yields 7 percent.
Current yield calculator
Current yield is the annual coupon over the price paid. A \$50 coupon costs 5.83 percent at a \$857.88 price and 4.27 percent at \$1,171.69.
Dividend yield calculator
Dividend yield is the annual dividend over the share price. A \$2 dividend on a \$41.60 share is 4.81 percent; \$1.50 on \$50 is 3 percent.
Earnings yield calculator
Earnings yield is EPS over price, the P/E upside down. \$2.50 of EPS on a \$50 share is 5 percent and a P/E of 20; \$4 on \$40 is 10 percent.
Graham number calculator
The Graham number is the square root of 22.5 times EPS times book value. \$2 of EPS with \$20 of book value per share gives \$30 a share.
Sortino ratio calculator
The Sortino ratio divides excess return by downside deviation alone. A 10 percent return against a 3 percent target with 8 percent downside gives 0.875.
Earnings per share calculator
EPS is net income divided by shares outstanding. \$10,000,000 of net income across 2,000,000 shares is \$5 a share, and \$2,400,000 across 800,000 shares is \$3.
Market cap calculator
Market capitalisation is price times shares outstanding. A \$50 share with 2,000,000 shares is \$100,000,000, and \$40 with 1,000,000 shares is \$40,000,000.
Modified duration calculator
Modified duration is Macaulay duration divided by one plus the periodic yield. A Macaulay of 7.5 at a 6 percent yield paid twice a year gives 7.2816.
Perpetuity calculator
A perpetuity is a payment divided by a rate. \$1,000 a year at 5 percent is worth \$20,000 today, and \$2,000 a year at 4 percent is worth \$50,000.
Business maths
Enterprise value and EV/EBITDA
Enterprise value is equity plus debt minus cash. Work the identity, then the EV/EBITDA multiple, on one sheet. The same bridge a deal model uses.
Unlevered free cash flow calculator
Free cash flow to the firm from EBIT, tax, D&A, capex and working capital. The unlevered cash a DCF discounts. Same bridge a deal model uses on a teaching sheet.
ROIC calculator and NOPAT split
Return on invested capital is NOPAT over invested capital. Work NOPAT from EBIT and tax, then the ratio. The number a cost of capital is compared with.
ROE calculator and formula
Return on equity is net income over book equity. Work a 15 percent sheet, then see why the same 15 percent on ROIC is a different claim with financial leverage sitting inside ROE.
Cash conversion cycle calculator
The cash conversion cycle is days sales plus days inventory, minus days payable. Work a 75 day cycle, then a negative one where suppliers fund the firm.
Interest coverage calculator
Interest coverage is EBIT divided by interest expense, the times-interest-earned ratio. Work an 8 times sheet, then see why a zero interest line is not infinity.
Unlevered beta calculator
Unlevered beta strips financial leverage out of an equity beta, assuming debt beta is zero. Work the Hamada identity, then relever at the same D/E to check it.
Offer premium calculator
Offer premium is the bid over the unaffected share price. Work a 30 percent premium, then a discount, on the close before the news leaked.
NPV calculator and net present value formula
Discount future cash flows to what they are worth today. Shows the NPV formula, the same project at 8 percent and at 12 percent, and the time-zero mistake.
IRR calculator: internal rate of return
Work out the internal rate of return on a project and test it against your cost of capital. Shows the formula, worked examples, and where IRR misleads.
WACC formula and calculator
Work out the weighted average cost of capital from the market value of equity and debt, the cost of each, and the tax relief on interest, with three worked examples.
Leverage ratio formula and calculator
The three leverage ratio formulas worked from one balance sheet: debt-to-equity, debt-to-assets and the equity multiplier, plus what a fall in asset values does to equity.
Break-even point calculator and formula
Work out how many units you have to sell to cover fixed and variable costs. Shows the break-even formula, contribution margin, a profit target and the rounding rule.
Payback period calculator and formula
Work out how long a project takes to return its own cost in cash, why the answer ignores everything after that date, and what to use instead when it matters.
Current ratio and gross margin calculator
Work out the current ratio, the quick ratio and the gross margin from a balance sheet and an income statement, and see why a good number depends on the industry.
ROA calculator and formula
Return on assets is net income over total assets. On \$45,000 of profit and \$800,000 of assets, ROA is 5.625 percent. Times the equity multiplier, that is the 15 percent ROE on the same sheet.
DuPont ROE calculator and formula
Work out ROE the DuPont way: net margin times asset turnover times the equity multiplier. Enter four figures and see which of the three is moving the return.
EV to sales calculator
EV/sales is enterprise value over sales. On \$100,000,000 of equity, \$40,000,000 of debt and \$10,000,000 of cash, EV is \$130,000,000. Against \$65,000,000 of sales that is 2 times.
Operating margin calculator
Operating margin is EBIT over sales. On \$100,000,000 of EBIT and \$500,000,000 of sales it is 20 percent. Add \$20,000,000 of D&A and EBITDA margin is 24 percent.
Payout ratio calculator
Payout is dividends over net income. On \$18,000 of dividends and \$45,000 of profit it is 40 percent. Retention is 60 percent. Times 15 percent ROE, sustainable growth is 9 percent.
FCF yield calculator
FCF yield is unlevered free cash flow over market cap. \$55,000,000 of FCF on \$1,100,000,000 of market cap is 5 percent. It is a cash rate on the equity value, not earnings yield.
Cash ratio calculator
The cash ratio is cash over current liabilities. \$200,000 of cash against \$400,000 of bills is 0.50. Current and quick ratios keep more of the current assets in.
Current ratio calculator
The current ratio is current assets over current liabilities. \$150,000 against \$100,000 of bills is 1.5, while \$80,000 against the same bills is 0.8.
Working capital calculator
Working capital is current assets minus current liabilities. \$150,000 less \$100,000 leaves \$50,000; with only \$80,000 of assets it is negative \$20,000.
Gross margin calculator
Gross margin is gross profit over sales. \$500,000 of sales less \$300,000 of cost leaves \$200,000 of gross profit, which is a 40 percent margin.
NOPAT calculator
NOPAT is operating profit after tax and before financing. \$100,000 of EBIT taxed at 21 percent is \$21,000 of tax and \$79,000 of NOPAT.
EV to EBITDA calculator
EV to EBITDA divides enterprise value by operating earnings. \$130,000,000 over \$10,000,000 is 13 times, and \$80,000,000 over \$8,000,000 is 10 times.
Annuity present value calculator
The present value of an annuity discounts every payment. \$1,000 a year for 10 years at 6 percent is worth \$7,360.09 today, and \$500 for 5 years at 8 percent is \$1,996.36.
Profitability index calculator
The profitability index is discounted inflows over the outlay. \$11,978.13 of inflows against a \$10,000 outlay is an index above 1 and \$1,978.13 of NPV.
Days sales outstanding calculator
DSO is receivables over sales times the days in the period. \$50,000 of receivables on \$400,000 of annual sales is 45.625 days of waiting.
Sustainable growth rate calculator
Sustainable growth is return on equity times the retention rate. A 15 percent ROE paying out 40 percent retains 60 percent, which supports 9 percent growth.
Sinking fund calculator
A sinking fund deposit is the payment that grows into a target. Reaching \$10,000 in 5 years at 6 percent needs \$1,773.96 a year, not a fifth of the target.