Free Financial Calculators
13 tools covering mortgages, debt payoff, loans, and compound interest. Every one runs instantly in your browser, shows the assumptions behind its numbers, and works without an account.
Mortgage & Home
Start with the full payment before the loan itself — taxes, insurance, and PMI decide affordability far more often than the rate does. If you have not committed yet, the rent vs buy comparison is the one to run first.
Mortgage Calculator
Your full monthly payment including property taxes, homeowners insurance, PMI, and HOA dues — not just principal and interest.
Mortgage Payoff Calculator
Already own? See how an extra monthly payment, a lump sum, or a biweekly schedule moves your payoff date and cuts total interest.
Biweekly Mortgage Calculator
Compare paying every two weeks against once a month, starting from a home price and down payment.
Mortgage Comparison Calculator
Put two or three loan scenarios side by side — a 15-year against a 30-year, or one rate against another.
Rent vs Buy Calculator
Still deciding? Compares the two on net worth rather than monthly payment, and finds the year buying pulls ahead.
Debt & Credit Cards
One card is a different problem from five. A single balance is about the shrinking minimum payment; several balances are about what order to attack them in, and the order matters less than the amount you send.
Credit Card Payoff Calculator
One card, modelled properly — including the shrinking minimum payment that stretches a balance out for decades.
Debt Snowball Calculator
Order several debts smallest balance first, for the early wins that keep a payoff plan alive.
Debt Avalanche Calculator
Order the same debts by interest rate instead — the sequence that costs the least in total interest.
Loans
Two questions live here: what a loan will cost before you sign it, and what paying extra does once you already have it. They need different tools.
Car Loan Calculator
Price a car before you sign: monthly payment, total interest, sales tax, and trade-in credit.
Auto Loan Payoff Calculator
Already financed? See what extra payments save, and the month you stop owing more than the car is worth.
Student Loan Payoff Calculator
What an extra payment or a lump sum does to your payoff date — and why forgiveness changes the answer entirely.
Loan Amortization Calculator
The principal and interest split of every single payment on any fixed-rate loan, with a full schedule.
Saving & Investing
The mirror image of the debt calculators — the same compounding, running in your favour. Useful for deciding whether extra debt payments or investing wins at your rate.
Mortgage Calculators by State
The same mortgage calculator with that state's average property tax rate and insurance costs already filled in, plus notes on local first-time buyer programs. If your state is not listed, the main mortgage calculator takes any tax rate you enter.
How These Calculators Work
Every number is reproducible. Each tool states the loan amount, rate, and term behind any figure it quotes, and the worked examples in the surrounding text are pinned in an automated test suite. If a number on a page changes, a test fails.
Nothing you type leaves your browser. The calculations run locally as you type. Balances, rates, and incomes are never sent to a server unless you sign in and explicitly save a calculation.
The assumptions are stated, including the unflattering ones. Where a model excludes something that would change the answer — the mortgage interest deduction in the rent vs buy comparison, daily compounding on credit cards — the page says so and explains which direction it biases the result.
These tools are for estimation and education. They are not financial advice, and they cannot account for your full circumstances. Confirm anything consequential with your lender, servicer, or a qualified advisor. More on how the calculators are built and who writes them.
Prefer to read first?
The Learn section covers the reasoning behind these tools — how amortization actually works, whether to take a 15-year or 30-year mortgage, and which debt payoff order suits you.