Finance Tool

Mortgage Calculator Free Online

Calculate monthly mortgage payment (principal + interest) using standard amortization. See total interest paid and total of all payments over the loan term.

Runs in browserLive calculationAmortizationPMT formula
%
years

Results

Monthly payment (P&I)
Total of all payments
Total interest paid
Months to payoff

Pro — bulk batch calculation, API access, history & favorites

API access · Priority queue · Team workspace

Upgrade — $19/mo

Mortgage Calculator Features

Standard Amortization

Uses PMT = P × r / (1 − (1+r)^−n) — the same formula banks use. Equal monthly payments throughout the term.

Principal + Interest

Calculates P&I only (not taxes, insurance, HOA, or PMI). Add ~$200–500/mo for a typical US property to estimate full housing cost.

Total Cost View

See total dollars paid over 30 years and how much is interest vs principal — often interest exceeds principal on a 30-year mortgage above 5%.

Live Calculation

Adjust any input, all values update instantly.

Realistic Defaults

Default $300k loan, 7% rate, 30 years — typical 2025 US mortgage scenario. Adjust to your numbers.

100% Private

All math runs in your browser.

Free vs Pro

FeatureFreePro
Full mortgage calculation
Live calculation
Quick presets
Bulk CSV / Excel calculation
REST API access
Save & share calculations

Frequently Asked Questions

Standard amortization formula: PMT = P × (r ÷ 12) ÷ [1 − (1 + r ÷ 12)^−(12n)] where P = loan amount, r = annual rate (decimal), n = years. Example: $300k @ 7%/30y = $1,996/mo.

No — only principal and interest (P&I). Add property tax, homeowners insurance, HOA fees, and PMI (if down payment < 20%). Total PITI is typically $200–600 more per month.

At 7%, you pay roughly the loan amount in interest. $300k @ 7%/30y = $418k interest, $718k total. At 3% it would be $155k interest, $455k total.

15 years has higher payments but ~half the total interest. $300k @ 7%/15y = $2,696/mo vs $1,996/mo for 30y, but interest is $185k vs $418k — savings of $233k over the loan.

Private Mortgage Insurance — required when down payment < 20%. Typically 0.5%–1.5% of loan/year, paid monthly until you reach 20% equity. Can be canceled at 22%.