Estimates only, not financial advice. Your lender’s rate, fees and rounding will differ; ask for an official quote before you sign.
This loan calculator works out the monthly payment, total interest and payoff date for any fixed-rate loan as you type, and builds a full amortization schedule you can open by year or download as CSV. Compare equal payments, equal principal and interest-only repayment, and see how an extra monthly payment shortens the loan.
How to use
- Loan: enter the amount, the yearly interest rate and the term in years or months. The monthly payment, total interest and payoff date appear at once.
- Add an extra monthly payment to see how much sooner you finish and how much interest you save.
- Mortgage: enter the home price and down payment (as % or amount), rate and term, then property tax, insurance, PMI and HOA to get the full monthly payment.
- Compound interest: enter a starting amount, a monthly deposit, the rate and years, and pick how often interest compounds. Move over the chart to read any year.
- Open a year in the table to see each month. Tap a row to copy it, or download the whole schedule as CSV.
- Payments use the standard fixed-rate (annuity) formula: P × r ÷ (1 − (1 + r)^−n), with r = yearly rate ÷ 12.
- PMI is added only when the down payment is under 20% and stops when the balance reaches 78% of the home price.
- Compound interest assumes deposits at the end of each month; the rate is converted to an equivalent monthly rate for the chosen compounding.
- Results don’t include origination fees, rate changes, inflation or taxes on interest.
- Rows and totals are rounded for display; the CSV keeps two decimals.
How the monthly payment is calculated
A fixed-rate loan with equal payments uses the annuity formula: payment = P × r ÷ (1 − (1 + r)^−n), where P is the amount borrowed, r the yearly rate divided by 12 and n the number of months. Borrowing 200,000 at 6% over 30 years gives 1,199.10 a month and 231,676 of interest over the life of the loan.
Early payments are mostly interest because interest is charged on a large balance; as the balance falls, more of each payment goes to principal. That is why extra payments early in a loan save the most.
Repayment methods compared
With equal principal, you repay the same share of principal each month plus interest on what is left, so payments start high and fall; on the same 200,000 loan that totals 180,500 in interest. Interest-only means paying 1,000 a month and the full principal at the end, the most expensive option at 360,000 in interest. Results do not include fees, rate changes or insurance, so compare them with the lender's APR.
Frequently asked questions
How is a monthly loan payment calculated?
With the annuity formula P × r ÷ (1 − (1 + r)^−n). For 200,000 at 6% over 360 months, r = 0.005 and the payment is 1,199.10.
What is an amortization schedule?
A table that splits every payment into interest and principal and shows the remaining balance after each month, from the first payment to the last.
How much do extra payments save?
Every extra amount goes straight to principal, so it cuts the interest on all later months. Enter an extra monthly payment to see the new payoff date and the interest saved.
What is the difference between APR and interest rate?
The interest rate sets the payment; the APR adds fees and some other costs, spread over the term. Use the APR to compare offers from different lenders.
Which repayment method costs the least interest?
Equal principal, because the balance falls fastest. Equal payments come next, and interest-only costs the most, since the full balance stays until the end.
Is my data stored anywhere?
No. The calculation runs in your browser and nothing you enter is sent to a server.