🏠 Mortgage Calculator (US)
Calculate your monthly repayment, total interest, and full amortisation schedule for any home loan.
A standard US 30-year fixed-rate mortgage amortises monthly using M = P × [r(1+r)^n] ÷ [(1+r)^n − 1]. The Freddie Mac Primary Mortgage Market Survey publishes the weekly national rate, and the FHFA sets the annual conforming loan limit ($832,750 in 2026, higher in designated high-cost areas).
The US 30-year fixed-rate mortgage is a uniquely American instrument. Most developed economies don't offer it because the prepayment optionality embedded in the borrower's right to refinance creates a risk profile no commercial lender wants to hold. The reason it exists in the US is securitisation through Fannie Mae and Freddie Mac, who absorb that prepayment risk through MBS pricing.
This calculator handles the loan products US homebuyers actually face:
- Conforming 30-year fixed — up to the FHFA's annual conforming loan limit, backed by Fannie/Freddie, lowest available rates, 20% down avoids PMI
- FHA — 3.5% minimum down with 580+ FICO; upfront 1.75% MIP plus annual MIP in the 0.15-0.75% range (most borrowers land near 0.55%), with MIP for the life of the loan if down payment is under 10%
- VA — for eligible veterans, active duty, and surviving spouses; 0% down, no PMI, with a one-time funding fee of 1.4-3.6% (waivable for disabled veterans)
- USDA Rural Development — 0% down in designated rural areas, income limits apply
- Jumbo — above the conforming limit, tighter qualification (700+ FICO, 20%+ down, 6-12 months reserves)
- ARMs (5/1, 7/1, 10/1) — fixed for the initial period, then resets annually against SOFR + margin
Beyond P&I, the calculator handles the rest of PITI and additional carrying costs: - Property tax — varies widely, from 0.3% (Hawaii) to over 2% (New Jersey, Illinois) of assessed value annually - Homeowners insurance — $1,200-2,500/year typical, materially higher in CA, FL, and coastal areas - PMI — 0.3-1.5% per year of the loan balance if down payment is under 20% on a conforming loan - HOA dues — where applicable, typically $200-800/month for condos and planned communities
The 28%/36% rule remains the lender baseline: housing should sit under 28% of gross monthly income, total debt under 36%. For loan-program details, the Consumer Financial Protection Bureau's mortgage guides and the FHFA's annual conforming loan limits page are the authoritative federal references.
Calculate your monthly repayment, total interest, and full amortisation schedule for any home loan.
How is a mortgage payment calculated?
A standard fixed-rate mortgage uses the amortising annuity formula: M = P × r(1+r)n / ((1+r)n−1), where P is the loan amount, r is the monthly interest rate (annual ÷ 12), and n is the total number of monthly payments. Most of each early payment goes to interest; the principal share grows over time.
| Item | Value |
|---|
| Month | Payment | Principal | Interest | Balance |
|---|
How to use this calculator
Takes about 3 minutes.
- Enter the home price and your down payment
- Set the annual interest rate and the loan term in years
- Optionally add monthly property tax and home insurance to get a full PITI figure
- Click Calculate to see your monthly payment, total interest, and full amortisation schedule
- Adjust the down payment or term and recalculate to compare scenarios
Try these scenarios
Tap a scenario to load it into the calculator above.
Methodology & Sources
This calculator implements the standard mortgage amortisation formula: M = P × [r(1+r)^n] / [(1+r)^n − 1]. Region-specific tax and rate defaults are sourced directly from each country's primary government source and reviewed against the publication date below.
- USA: IRS — federal income tax brackets and contribution limits.
- UK: GOV.UK — HMRC personal allowance, National Insurance, and dividend rates.
- SA: SARS — personal income tax brackets and tax rebates.
Last verified: May 2026.
Key concepts
Principal vs. interest. Every mortgage payment is split between principal (reducing what you owe) and interest (the lender's fee). Early in a 30-year loan, most of each payment is interest; only after 15+ years does principal start dominating — this is the amortisation curve.
LTV (loan-to-value). Your loan divided by the home's price. A 20% deposit gives an 80% LTV. In the US, an LTV above 80% triggers Private Mortgage Insurance (PMI); in the UK, lower LTV typically unlocks better rates (FCA rules).
Fixed vs. variable rate. A fixed rate locks your payment for the fix period (typically 2, 5, or 10 years in the UK; whole-term in the US). A variable rate moves with central-bank policy — cheaper when rates fall, painful when they rise.
PITI and escrow. In the US, lenders often bundle property tax and homeowner's insurance into your monthly payment via an escrow account — Principal, Interest, Taxes, Insurance. The calculator's optional fields add these for a true monthly housing cost.
Total interest paid. Over a 30-year, $400k loan at 7%, you may pay more in interest than the home cost. Shortening to 15 years roughly halves total interest at the cost of a higher monthly payment.
Frequently Asked Questions
Last reviewed: · See editorial policy