Calculators
Thirteen free calculators, grouped by the decision you're trying to make. No signup — pick one and start typing.
Get out of debt
Avalanche vs Snowball
Compare avalanche vs snowball payoff strategies side by side — months, interest, and payoff order for each.
Run the numbers →Balance Transfer Analyzer
0% balance transfer or stay put? See the fee, interest avoided, and the payment needed to beat the promo clock.
Run the numbers →0% Promo Juggler
Juggling several 0% promos? One payment plan that clears every balance before the clocks run out.
Run the numbers →Debt vs Invest
Pay down debt or invest the extra cash? Compare net worth, interest paid, and the breakeven return.
Run the numbers →Investing & retirement
Compound Growth
What could your money grow to? Future value, year-by-year growth, and the true cost of waiting.
Run the numbers →Roth vs Traditional
Roth or Traditional retirement account? Compare after-tax values side by side at your tax rates.
Run the numbers →FIRE Number
Your FIRE number, years to financial independence, and projected FI date — from your spending and savings rate.
Run the numbers →Housing
Rent vs Buy
Renting or buying? Breakeven year, total costs, and equity built — side by side for your stay.
Run the numbers →Home Equity
How much equity do you have — and what could you borrow against it? LTV, 80% CLTV limits, HELOC estimates.
Run the numbers →Refinance Analyzer
Should you refinance? Monthly savings, breakeven point, and total interest over the years you'll stay.
Run the numbers →Mortgage Payoff
What extra mortgage payments do for you: months shaved off, interest saved, and your new payoff date.
Run the numbers →Loans & taxes
Get the free Debt Payoff Planner spreadsheet
Our most popular calculator, as a spreadsheet you can keep: list your debts, pick avalanche or snowball, and see your debt-free date. Free — delivered by email.
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Guides
Plain-English explainers on the forces moving your money — then jump into the calculator that applies them.
How Bond Yields Affect You
How bond yields quietly set your mortgage rate, savings yield, and 401(k) bond value — the transmission chain in plain English.
Read the guide →Fed Rate Changes & Your Wallet
How Fed rate moves pass through to your credit card APR, HELOC payment, and savings yield.
Read the guide →Inflation, Plain English
Why inflation shrinks what each dollar buys — and how TIPS and I-bonds are designed.
Read the guide →Why MoneyMath
Free, always
Every calculator is free. No paywalls, no trials, no "premium results."
No signup to calculate
Open a tool and start typing. Your numbers never leave your browser.
Shows its work
Every calculator includes a methodology note with its formulas and assumptions — so you can check the math.
MoneyMath may earn a commission if you apply through sponsored links on this site, at no cost to you.
FAQ
Are the MoneyMath calculators really free?
Yes. Every calculator is free to use with no account or signup. We may earn a commission if you apply for a product through a sponsored link, at no cost to you.
Is MoneyMath financial advice?
No. MoneyMath provides educational calculators only. This is not financial, tax, or legal advice. Results are simplified estimates — verify important decisions with a qualified professional.
How accurate are the calculators?
The calculators use standard financial math — amortization, compound interest, and payoff simulations — and each one includes a methodology note showing its formulas and assumptions. Treat results as planning estimates, not bank statements.
Do I need to sign up to use the calculators?
No. You never need an account to run a calculation. An email address is only needed if you want the free Debt Payoff Planner spreadsheet delivered to you.