Mortgage Calculator
Estimate a fixed monthly principal-and-interest payment, total interest and the remaining balance by year.
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Quick summary: Estimate a fixed monthly principal-and-interest payment, total interest and the remaining balance by year.
Read the complete guide
Updated reference sections in this guide are in English.
What the payment includes
Enter the amount borrowed, the fixed annual interest rate and the loan term in whole years. The result estimates the monthly payment required to repay the principal over that term with interest charged monthly. The same arithmetic can illustrate a conventional fixed-rate mortgage or another fully amortizing loan with the stated assumptions. It does not produce a lender offer or an affordability approval.
The amortization formula
Monthly payment M = P × r ÷ [1 − (1 + r)−n]
At 0% interest: M = P ÷ n
Total interest = M × n − P
P is the loan principal. Each month, the model charges interest on the outstanding balance, then applies the rest of the payment to principal. Interest is a larger share of the early payments because the outstanding balance is larger. The table shows the remaining principal after each full year.
A payment and its first-month split
300,000 borrowed at 6.5% for 30 years
The monthly principal-and-interest payment is approximately 1,896.20. First-month interest is 300,000 × 0.065 ÷ 12 = 1,625.00; about 271.20 of that first payment reduces principal. Later payments apply more to principal as the balance falls.
A zero-interest check
A 100,000 loan repaid over 10 years at 0% has 120 monthly payments. The unrounded monthly amount is 100,000 ÷ 120 = 833.3333…, displayed as 833.33. Total modeled interest is zero.
Check this scenario in the calculator:
- Loan amount
- 300000
- Annual interest rate (%)
- 6.5
- Term (whole years)
- 30
- Currency (display only)
- USD — US dollar
Separate the loan payment from ownership costs
A principal-and-interest estimate is only part of a homeownership budget. Property taxes, homeowners insurance, mortgage insurance, association charges and maintenance can add costs. Some are collected with a loan payment and others are paid separately. Keep those figures separate when comparing the result with a lender disclosure or a household budget.
Model boundaries and rounding
The model assumes a fixed rate, monthly scheduled payments, no missed payments and no extra principal payments. It excludes fees, points, escrow, balloon payments and rate resets. The annual rate here is the rate used to accrue interest, not an all-in APR including fees. Payments and balances are calculated without rounding every monthly transaction to cents, so a lender’s payment schedule and final installment can differ slightly. A term from 1 to 100 whole years is supported.
Reference and loan questions
CFPB: how mortgage lenders calculate monthly payments and CFPB: principal and interest versus the total payment explain the payment structure and additional costs. The formula and examples above specify this tool’s calculation.
Does selecting EGP convert a dollar loan?
No. The currency selection only labels the amounts. Enter all values in one currency.
Can I enter an adjustable-rate loan?
This form models one fixed rate throughout. It does not simulate future rate changes.
Why does the remaining balance finish at zero?
The payment formula is designed to amortize the loan across the selected number of monthly payments; small numerical residue at the final payment is cleared.