Simple Interest Calculator
Calculate interest without compounding and see the principal, interest, total amount due, daily interest, and monthly equivalent.
Open calculator →Calculator library
Free loan and interest calculators
Calculate payments, daily interest, compound growth, extra-payment savings, balloon balances, refinance break-even, Rule of 78 allocations, and more. Every calculator includes a formula, example, table, and links to related tools.
Interest calculators
Calculate simple, compound, and daily interest using clear formulas and worked examples.
Compound Interest Calculator
Estimate future value, total contributions, interest earned, and year-by-year growth with periodic compounding.
Open calculator →Daily Interest Calculator
Convert an annual rate to a daily rate and compare how common day-count bases change the interest for a selected number of days.
Open calculator →Loan calculators
Solve for a regular payment or determine the balance remaining after selected payments.
Loan Payment Calculator
Solve for the regular payment, total interest, total payments, payoff time, and complete amortization schedule.
Open calculator →Remaining Loan Balance Calculator
Find the estimated balance at a specific payment number without manually reading an entire amortization schedule.
Open calculator →Payoff calculators
Compare extra-payment, biweekly, payoff, and refinance strategies.
Extra Payment Calculator
See how recurring extra principal and a one-time lump sum can shorten a loan and reduce total interest.
Open calculator →Biweekly Payment Calculator
Compare three commonly confused payment strategies and see how an accelerated biweekly plan creates the equivalent of one extra monthly payment each year.
Open calculator →Loan Payoff Calculator
Use the current balance and payment rather than the original loan terms to estimate the remaining payoff path.
Open calculator →Refinance Calculator
Compare both the monthly-payment effect and the long-term cost before replacing an existing loan.
Open calculator →Specialty loan calculators
Estimate Rule of 78 allocations, balloon balances, and interest-only payment changes.
Rule of 78 Calculator
See how a precomputed finance charge is weighted toward earlier payments and estimate the unearned interest remaining after a selected payment.
Open calculator →Balloon Payment Calculator
Estimate the regular monthly payment, interest paid before the balloon date, and the lump-sum balance due at payoff.
Open calculator →Interest-Only Loan Calculator
Estimate the low payment during an interest-only period and the higher payment required when principal repayment begins.
Open calculator →Simple calculators for quick answers. Amortization Pro for detailed work.
The web calculators are free and run in your browser. Download the Windows software when you need editable payment rows, saved loan files, CSV export, and full printable reports.
How to use the calculator library
Choose the calculator that answers one question, review the assumptions below the results, and move to the full schedule calculator when payment-by-payment detail is needed.
Choose one question
Start with payment, interest, remaining balance, payoff, or refinance rather than entering unnecessary information.
Review the formula
Each calculator explains the method and provides an example so you can understand the result instead of accepting a number blindly.
Confirm contract details
Compare estimates with the note, lender statement, payoff quote, day-count convention, fees, and payment-crediting rules.