Mortgage Payment Calculator — P&I, Tax & Insurance
Calculate your real monthly mortgage payment: principal & interest plus property tax, insurance and HOA — and the total cost of the loan.
Last reviewed 2026-10-18. Rates change — verify against the official sources linked below before relying on these figures.
What this is based on
- Standard fixed-rate amortizing mortgage — P&I via M = P·r(1+r)ⁿ÷((1+r)ⁿ−1).
- PMI (typically 0.5–1%/yr when down payment <20%) is not included — add it to insurance if it applies.
- ARMs, points, and closing costs are excluded.
P&I is only part of the check you'll write
The number lenders quote — principal & interest — is usually 70–80% of the real monthly outlay. On a $350k home with 20% down at 6.5% for 30 years, P&I is ~$1,770. Add $4,200/year property tax and $1,800 insurance+HOA and you're writing $2,270 checks. The full PITI is what affordability actually means.
And if your down payment is under 20%, add PMI: typically 0.5–1% of the loan per year — another $115–230/month on this loan until you hit 78–80% equity.
The interest number that changes behavior
On a $280k 30-year mortgage at 6.5%, total interest is ~$357,000 — you pay back 2.27× what you borrowed. Same loan at 15 years: payment jumps to ~$2,440 but total interest collapses to ~$159,000. The 15-year costs 38% more monthly and saves ~$198k — the single largest financial decision most people make is that term toggle.
Even 0.5% on the rate moves the needle hard: 6.0% vs 6.5% on this loan saves ~$34,000 over 30 years — which is why rate-shopping three lenders is worth more than most financial advice you'll ever get.
The extra-payment math
Every extra principal dollar stops accruing interest for the rest of the term. Just $200/month extra on this loan cuts ~6 years off the schedule and saves ~$80k in interest. Biweekly payments (26 half-payments = 13 full payments a year) achieve a similar effect almost invisibly.
Frequently asked questions
- How much is a $300,000 mortgage per month?
- At 6.5% for 30 years: ~$1,896 P&I, or roughly $2,350–2,550 with typical taxes and insurance. At 15 years: ~$2,613 P&I but less than half the total interest.
- How is a mortgage payment calculated?
- M = P·r(1+r)ⁿ ÷ ((1+r)ⁿ−1) on the loan amount (price minus down payment), where r is the monthly rate and n is months. Taxes and insurance are added on top.
- What is PITI?
- Principal, Interest, Taxes, Insurance — the full monthly housing cost, which is what lenders use for the 28% debt-to-income affordability guideline.
- Is a 15 or 30 year mortgage better?
- 15-year: higher payment, ~half the interest, forced equity building. 30-year: flexibility — you can always pay extra and simulate the 15-year schedule while keeping the option to pay less.
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