Finance calculators that show their work
Free tools for compound interest, loan payments, debt payoff, and retirement planning. No signup, no email, no stored data — every calculation runs in your browser, and every tool explains the formula behind it.
Saving & Investing
Compound Interest Calculator
See how an initial deposit plus regular contributions grows over time, and how much of the final balance is interest rather than your own money.
Savings Goal Calculator
Find out how long it takes to reach a savings target — and how much you'd need to set aside each month to hit it by a specific date.
Emergency Fund Calculator
Work out how large your emergency fund should be based on your actual essential expenses, and how long it will take to build at your current savings rate.
Investment Risk vs. Return Comparison
Compare how conservative, moderate, and aggressive asset mixes have historically behaved — the likely range of outcomes, and the losses each one has survived.
CD & High-Yield Savings Calculator
Calculate what a certificate of deposit or high-yield savings account earns — and whether it's actually beating inflation after tax.
Retirement
Retirement Savings Calculator
Project what you'll have at retirement, and what that balance translates to as sustainable annual income.
401(k) Employer Match Calculator
Find out whether you're capturing your full employer match — and what any match you're leaving behind would be worth by retirement.
Roth vs. Traditional Calculator
Compare after-tax retirement income from a Roth and a traditional account — including what happens if you invest the traditional account's tax refund.
FIRE Calculator: Financial Independence Date
Find out how many years until your investments could cover your expenses — and how much your savings rate, rather than your income, drives that date.
Loans & Debt
Loan Payment Calculator with Extra Payments
Work out the monthly payment on any amortising loan, then see what happens when you pay a little extra each month.
Credit Card & Debt Payoff Calculator
Enter a balance, its interest rate, and what you can pay monthly. See the payoff date, the true interest cost, and what paying extra would change.
Credit Card Minimum Payment Calculator
See what happens if you only ever pay the minimum — and how much a small fixed payment instead would save you.
Student Loan Payoff Calculator
See your payoff date and total interest on a standard repayment plan, and what paying extra each month would change.
Debt Consolidation Calculator
Compare keeping your current debts against rolling them into one consolidation loan — including the origination fee most calculators ignore.
Auto
Car Payment Calculator
Work out your monthly car payment including tax, trade-in, and fees — then see when you'd stop owing more than the car is worth.
How Much Car Can I Afford?
Find your realistic car budget from your income — including insurance, fuel, and maintenance, which the monthly payment alone hides.
Home & Property
How Much House Can I Afford?
Work out your maximum home price from your income, debts, and down payment — including property tax and insurance, which most affordability calculators leave out.
Rent vs. Buy Calculator
Compare the true cost of renting against buying over the years you'd actually stay — including closing costs, maintenance, and what your down payment would have earned invested.
Mortgage Refinance Calculator
Work out your break-even point on a refinance — how long you must stay to recover the closing costs, and whether resetting the term erases the savings.
Budgeting
Business
ROI Calculator
Calculate return on investment as both a simple percentage and an annualised rate — the second is the only one that lets you compare investments of different lengths.
Break-Even Point Calculator
Find how many units you must sell to cover your costs, and how much revenue that represents — plus the margin of safety you have at your current sales.
Planning
Net Worth Calculator
Add up what you own and subtract what you owe — then see how much of your wealth is actually liquid.
Salary to Hourly Calculator
Convert an annual salary to a real hourly rate — including unpaid overtime and commuting, which is what actually determines what your time earns.
Is My Raise Actually a Pay Cut?
Compare your raise against inflation to see whether your purchasing power went up or down — and what a run of below-inflation raises costs over a career.
Inflation Calculator: Future Purchasing Power
See what a sum of money will actually be worth after inflation, and what today's expenses will cost you years from now.
Why these calculators
Most finance calculators give you a number and nothing else. These give you the number, the assumptions behind it, a year-by-year breakdown you can inspect, and a written explanation of what the maths is actually doing — so you can check the result rather than trust it.
26 calculators and counting. Browse all →