Mortgage Calculator
Estimate payment
Results
| Principal & interest (P&I) | — |
|---|---|
| Property tax (mo.) | — |
| Home insurance (mo.) | — |
| Estimated total / month | — |
How to Use This Mortgage Calculator
Staring at a home listing price tells you almost nothing about what you will actually write a check for each month. Between the down payment math, P&I, and escrow lines, it is easy to lose track. Enter your scenario here and get a clean breakdown before you call a lender.
- Enter home price. Use the purchase price or appraised value you are modeling.
- Set down payment in dollars or percent. Toggle between a fixed cash amount and a percentage of home price—the hint updates to match your mode.
- Enter loan term and interest rate. Defaults are 30 years at 6% APR; adjust to your quote.
- Optionally add annual tax and insurance. Each is divided by 12 and added to the monthly total as escrow-style estimates.
- Press Calculate. Review P&I, tax, insurance, and estimated total. Use Share Calculation to copy a link with your inputs.
For charts and a balance curve, try the Mortgage Payment Calculator. To see how extra payments shorten the term, open the Mortgage Payoff Calculator.
Mortgage Formulas and Practical Applications
Your monthly mortgage payment in this tool has two layers. P&I repays the loan and pays lender interest—think of it as the part that actually shrinks what you owe. Optional tax and insurance are split into twelve equal monthly amounts, like a lender escrow account would, though your servicer may adjust those as bills come due.
Loan principal and monthly rate
Principal is home price minus down payment. The monthly rate converts your annual APR into a per-payment figure:
P = Home Price − Down Payment
i = APR / 100 / 12
n = Term in Years × 12
Fixed-rate P&I payment
For a standard fully amortizing loan, solve for payment M so the balance reaches zero after n payments:
M = P × [ i(1 + i)ⁿ ] / [ (1 + i)ⁿ − 1 ]
Home $400,000, down $80,000, loan $320,000, APR 6%, 30 years → P&I about $1,918.56/month. Add $3,600/year tax and $1,200/year insurance for a rough $2,318.56 total.
What this calculator does not include
PMI/MIP, HOA dues, lender fees, discount points, and irregular escrow true-ups are not modeled. Closing costs and APR vs. note rate nuances can differ from a Loan Estimate. Always confirm with your lender.
Frequently Asked Questions
How do you calculate a monthly mortgage payment?
Loan principal P is home price minus down payment. Principal-and-interest uses M = P × [ i (1 + i)^n ] / [ (1 + i)^n − 1 ], where i is the monthly interest rate (annual percent ÷ 100 ÷ 12) and n is months (years × 12). Optional annual property tax and insurance are each divided by 12 and added for a total monthly estimate. Mortgage insurance (PMI/MIP) is not included here.
How can I lower my monthly mortgage payment?
Borrow less (lower price or larger down payment), qualify for a lower rate, or choose a longer term—though a longer term often increases total interest paid. Escrow parts change when tax or insurance estimates change. This tool does not model lender fees or mortgage insurance.
Does mortgage insurance affect the calculation?
RapidRatio does not add PMI, MIP, or similar mortgage insurance. If your loan requires it, your real monthly payment can be higher than the total shown here until insurance drops off or you refinance.
Does this calculator include property taxes and homeowners insurance?
P&I is always computed. You may optionally enter annual property tax and annual homeowners insurance; each is divided by 12 and added to the breakdown. Leave those fields blank for P&I only.
What does RapidRatio use for numeric accuracy?
Typed inputs stay in text form until evaluated in a decimal-first workspace. Principal, interest, term, and monthly tax or insurance splits are carried consistently through formatting so stray browser rounding is less likely to affect what you read on the screen.