Mortgage Payment Calculator
Calculate your monthly mortgage payment (principal & interest), total interest and total amount paid from the loan amount, interest rate and term.
Inputs
Report details (optional — appears on the PDF report)
Results
Formula
- P = loan amount
- r = monthly rate = annual rate / 12 / 100
- n = term in months
How It Works
This is the standard fixed-rate amortization formula. Each monthly payment covers that month's interest on the remaining balance plus a portion of principal, so the balance falls to zero exactly at the end of the term.
Total paid is M × n; total interest is that amount minus the loan.
Worked Example
Given: Loan $320,000, rate 6.5% p.a., 30 years (360 months)
r = 6.5/12/100 = 0.005417 · (1+r)360 = 6.993
M = 320,000 × 0.005417 × 6.993 / (6.993 − 1) ≈ $2,023
Total paid ≈ $728,100 · Total interest ≈ $408,100
Engineering Notes
- Covers principal & interest only — property tax, insurance, PMI and HOA are extra.
- Assumes a fixed rate for the whole term; adjustable-rate loans differ after the fixed period.
- Extra principal payments shorten the payoff and reduce total interest.
FAQ
Why is early-term payment mostly interest?
Interest is charged on the outstanding balance, which is largest at the start.
How much does the rate matter?
On long terms, even 0.5% changes the payment noticeably and total interest by tens of thousands.
Does this include taxes and insurance?
No — use the full Mortgage Calculator for the complete PITI payment.
Related Calculators
This calculator uses established formulas and standard calculation methods to provide reliable results for planning, estimation and reference.