Mortgage Calculator — Monthly Payment, Amortization & Extra Payments
Mortgage payment calculator for P&I, amortization, and extra principal on US home loans. Try free—no signup.
Last updated 2026-05-28 · Davi Baptista
Read also: Full calculator guide, Mortgage refinance calculator, HELOC payment calculator, Mortgage affordability calculator, Refinance & mortgage guide, Guia de financiamento e parcela, Alugar vs comprar imóvel, Juros compostos
How it works
A mortgage payment calculator estimates fixed-rate principal-and-interest, total interest, and payoff date with optional extra principal—P&I only, not escrow or PMI.
This mortgage calculator and mortgage payment calculator estimates principal-and-interest payment, total interest, and payoff date on a fixed-rate home loan. A home loan calculator should show how extra payments shorten the schedule—not just the baseline payment. Enter loan amount, annual rate, term in years, and optional extra principal to model US 30-year and 15-year mortgages, auto loans, and personal installment debt. Monthly mortgage calculator outputs are P&I only—add taxes, insurance, and PMI separately for full housing cost. Compare with mortgage affordability for max price and rent vs buy for ownership timing.
Mortgage payment math: P&I, interest, and prepayment
A fixed-rate mortgage splits each payment into interest on the remaining balance and principal reduction. Early years are interest-heavy; later years retire principal faster—this mortgage calculator shows that schedule.
The monthly number here is principal and interest only. Budget separately for property tax, insurance, PMI when down payment is under 20%, and HOA if applicable.
Extra payments toward principal shorten the loan and cut total interest—confirm your servicer applies them correctly. Even modest monthly extras on a 30-year note can save five figures over time.
Compare your rate to market before aggressive prepayment: refinance break-even may beat sending extra to a high-rate loan. Pair with rent vs buy if you have not decided to purchase yet.
Guide, examples, and methodology
Mortgage payment calculator
Enter loan amount, fixed APR, and term to see principal-and-interest payment, total interest, and amortization. A mortgage payment calculator is the baseline before you add tax, insurance, and HOA for full housing cost.
Home loan calculator
Compare 15-year versus 30-year terms on the same balance—shorter terms raise payment but often cut total interest sharply. Pair with our refinance and affordability tools when shopping rates.
Monthly mortgage calculator
Monthly mortgage calculator output here is principal and interest only—add property tax, homeowners insurance, HOA, and PMI for the full housing bill lenders use in DTI. Run the same loan amount at ±0.5% APR to see payment sensitivity before you lock a rate.
Amortization calculator mortgage
The amortization schedule shows how early payments skew toward interest and later payments toward principal. Model a recurring extra principal payment to see months saved and interest avoided—many servicers require you to designate extra amounts explicitly.
How to use this mortgage payment calculator
Enter loan amount (home price minus down payment for mortgages), annual interest rate, term in years, and optional extra monthly payment toward principal. This mortgage calculator outputs fixed-rate principal-and-interest payment, total interest over the life of the loan, and how extra payments shorten the schedule. Use it for US 30-year and 15-year mortgages, auto loans, and personal installment debt that amortizes on a standard schedule.
Example (USD): $350,000 mortgage
| Scenario | Inputs | Outcome |
|---|---|---|
| 30-year fixed | 6.5% APR | ~$2,212/mo P&I |
| 15-year fixed | 6.0% APR | ~$2,953/mo P&I, less total interest |
| +$200/mo extra | On 30-year above | Pays off years earlier; five figures saved |
Mortgage payment vs full housing cost
Lenders quote principal and interest (P&I). Your all-in payment adds property tax, homeowners insurance, HOA dues, and private mortgage insurance (PMI) when down payment is under 20%. This home loan calculator does not model escrow or PMI—add those manually when comparing to rent or setting a budget. For max price from income, use our mortgage affordability calculator first, then plug the loan amount here.
How we calculate amortization
Each month, interest accrues on the remaining balance at rate ÷ 12; the rest of the payment reduces principal. Extra payments in this model go 100% to principal starting the next month. We do not model ARM rate resets, interest-only periods, balloon payments, or biweekly servicer quirks—confirm prepayment application with your loan servicer.
15-year vs 30-year mortgages
A 15-year note typically carries a lower rate but a higher payment because principal retires faster. Total interest is often dramatically lower. Run both terms here with the same loan amount to see the payment gap versus lifetime interest savings—many buyers choose 30-year for cash flow then add voluntary extra principal.
When to pair with refinance math
If your rate is above current market quotes, compare break-even on our refinance savings calculator before sending large prepayments to a high-rate loan. Refinancing resets the amortization clock unless you keep the same term—closing costs matter. HELOCs and second liens are modeled separately on our HELOC payment calculator.
Common mistakes
- Treating P&I as the full monthly housing cost without tax and insurance.
- Assuming extra payments auto-apply to principal without confirming servicer settings.
- Comparing a 7% personal loan APR to a 6.5% mortgage without reading fee disclosures.
- Refinancing to lower payment while extending term and paying more lifetime interest.
- Ignoring rent-vs-buy timing when the real question is whether to purchase at all.
Related calculators in this topic
- Rent vs Buy Calculator
- Mortgage Affordability Calculator
- Free Mortgage Points Calculator
- HELOC Payment Calculator
Frequently asked questions
What is included in a mortgage payment?
Most US mortgages bundle principal, interest, taxes, and insurance (PITI) in escrow. This calculator shows P&I only—add tax, insurance, PMI, and HOA for the number on your monthly budget.
How do I calculate my monthly loan payment?
Monthly payment depends on principal P, annual rate r, and term n (months). Formula: M = P × [r/12 × (1+r/12)^n] / [(1+r/12)^n − 1]. Our calculator applies this instantly from your inputs.
How much total interest will I pay on my loan?
Total interest = (monthly payment × number of payments) − original loan amount. On a $20,000 loan at 7% for 5 years, total interest is about $3,761. The amortization table shows the interest portion of every payment.
Does making extra payments really save money?
Yes. On a $20,000 loan at 7% over 5 years, adding $100/month extra cuts payoff by about 13 months and saves roughly $640 in interest. Earlier extra payments have more impact because they reduce principal when interest charges are highest.
What's the difference between APR and interest rate?
The interest rate is the base borrowing cost. APR includes fees (origination, etc.), so it reflects the true annual cost. Use APR when comparing loan offers.