Calculators
Pick a tool below. Each page includes inputs, clear results, and the calculation assumptions. For mortgage questions like "amortization with extra payments", "one extra payment per year", and "biweekly vs extra principal", start with the mortgage tools and compare scenarios.
Popular entry points include the credit card payoff calculator and APR calculator, plus the biweekly mortgage calculator.
Start here
If you're comparing offers or planning payoff strategies, these short guides explain the concepts behind the calculators and link to the right tool for your situation.
Prefer a workflow view? Browse Topics for the APR calculator, credit card payoff calculator, rent vs buy calculator, and mortgage payoff calculator.
How to get better answers
- Use the same assumptions when comparing offers (term, fees, payment schedule).
- Prefer real statement numbers for balances and APRs (not marketing rates).
- Run a baseline, then change one input at a time (payment, rate, fee, or extra amount).
Mortgage payoff workflow
- Estimate your baseline monthly cost (PITI + PMI) in the Mortgage Payment Calculator.
- See the principal-and-interest table in the Amortization Schedule Calculator.
- Compare extra principal scenarios (monthly extra, lump sum, or one extra payment per year) in the Extra Payment Mortgage Calculator.
- If you're considering biweekly payments, compare to an equivalent monthly extra in the Biweekly Mortgage Payment Calculator.
If your lender offers biweekly programs, confirm whether payments are posted immediately or held and posted monthly.
Quick guide
- Paying off one card with a fixed payment: credit card payoff calculator.
- Paying off many debts: Snowball vs Avalanche.
- Shopping for loans: compare APR calculator (includes fees).
- Home buying: estimate monthly payment, then review the amortization schedule.
- Rent vs buy: start with the rent vs buy calculator and the break-even guide.
What to verify
Lenders and card issuers may use different rounding, PMI rules, escrow assumptions, and fee structures. Treat results as estimates and confirm final terms before making decisions.