Money math, answered in real time.
Every calculator updates as you type. On most, leave a number blank and it’s solved for you: the rate you need, the payment you can afford, the years it takes. Comparisons like rent vs. buy show the winner and the break-even point. No sign-up, and nothing leaves your browser.
Popular: Compound interest calculator Rule of 72 Mortgage calculator S&P 500 CAGR
Grow your money
Savings, interest and market returns
Compound Interest Calculator
See what savings grow to, or solve for the monthly amount, return or time to reach a goal.
Most popularCD Calculator
Interest and balance at maturity for any certificate of deposit, plus the cost of cashing out early.
NewCD Ladder Calculator
Split savings across CDs so one matures every year or few months, with interest and dates for each rung.
NewHigh-Yield Savings Calculator
Balance and interest per month at any APY, against the national average savings rate.
NewAPY Calculator
Turn an interest rate into APY for any compounding, or find the rate behind an APY.
NewRule of 72 Calculator
Years to double, triple or quadruple by the Rules of 72, 114 and 144, beside the exact math and the error.
Rule vs. exactS&P 500 Return Calculator
What a lump sum and monthly investing grew to since 1871, with dividends and inflation. Or solve a fixed-return plan.
Real data since 1871Inflation Calculator (CPI)
What a dollar in any year since 1870 is worth today, or what today’s money will cost later at any inflation rate.
4-way solverDividend Growth & DRIP
Portfolio value and passive income from growing dividends, reinvested or paid out, after dividend tax.
DRIP simulatorSCHD Dividend Calculator
What your SCHD shares pay each quarter and year, with its dividend history since 2012.
NewPlan retirement
Early retirement and tax-smart saving
FIRE Calculator
Years to financial independence, the savings it takes, or the budget your plan supports. FI and CoastFIRE numbers included.
5-way solverCoast FIRE Calculator
The age you can stop saving for retirement and let what you’ve invested grow on its own, checked against market history.
NewBarista FIRE Calculator
The portfolio that lets part-time work cover the rest of your spending, and the age you get there.
NewHow Long Will My Money Last?
Years your savings last at your monthly withdrawal as prices rise, and what you could spend to make them last.
NewRoth vs. Traditional
Pay tax now or later? See which leaves you more after tax, by how much, and your break-even retirement tax rate.
2026 tax bracketsBorrow smarter
Mortgages, debt payoff, and renting vs. buying
Mortgage Calculator & Affordability Solver
Payment, how much house you can afford, the down payment you need, payoff time or the rate behind a quote.
5-way solverMortgage Payoff Calculator
How much sooner extra payments clear your mortgage and the interest they save, or the extra it takes to hit a goal.
NewDebt Payoff Calculator
Your debt-free date, the payment or extra payment a deadline needs, or snowball vs. avalanche across all your debts.
5-way solverDebt Snowball Calculator
Your payoff order, debt-free date and what to pay on each debt every month.
NewRent vs. Buy
Owning a home against renting and investing the difference: who wins, by how much, and the break-even year.
Net worth comparisonValue investments
What is a stock actually worth?
DCF Intrinsic Value Calculator
A stock’s intrinsic value and margin of safety, or the growth and return its share price implies, with a sensitivity grid.
Reverse DCFReverse DCF Calculator
Start from a stock’s price and solve for the cash flow growth it assumes, or the return it offers.
Implied growthNo calculator matches that search yet. Try “interest”, “mortgage”, “retire” or “stocks”.
Live, no Calculate button
Results update on every keystroke, with charts and a plain-English summary.
Solve for any blank
Leave one number empty and it’s solved, using exact formulas or a bisection search that can’t run away.
Private by design
All math runs in your browser. Nothing you type is stored or sent anywhere.
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Your inputs live in the link. Bookmark it, or send it to your partner or advisor.