Mortgage Calculator
Work out the monthly payment on a mortgage and — the part that actually decides the deal — how much of it is interest. Over 30 years the interest can rival the price of the house itself.
Your numbers
Result
- Loan amount
- $240,000.00
- Down payment
- $60,000.00
- Total paid over the term
- $535,583.09
| Month | Payment | Interest | Principal | Balance |
|---|---|---|---|---|
| 1 | $1,487.73 | $1,262.81 | $224.92 | $239,775.08 |
| 2 | $1,487.73 | $1,261.62 | $226.11 | $239,548.97 |
| 3 | $1,487.73 | $1,260.43 | $227.30 | $239,321.67 |
| 4 | $1,487.73 | $1,259.24 | $228.49 | $239,093.18 |
| 5 | $1,487.73 | $1,258.04 | $229.70 | $238,863.48 |
| 6 | $1,487.73 | $1,256.83 | $230.90 | $238,632.58 |
| 7 | $1,487.73 | $1,255.61 | $232.12 | $238,400.46 |
| 8 | $1,487.73 | $1,254.39 | $233.34 | $238,167.12 |
| 9 | $1,487.73 | $1,253.16 | $234.57 | $237,932.55 |
| 10 | $1,487.73 | $1,251.93 | $235.80 | $237,696.75 |
| 11 | $1,487.73 | $1,250.69 | $237.04 | $237,459.70 |
| 12 | $1,487.73 | $1,249.44 | $238.29 | $237,221.41 |
How the payment is calculated
A fixed-rate mortgage uses the standard amortization formula:
payment = L × i / (1 - (1 + i)^-n)
where L is the loan (price minus down payment), i the monthly rate and n the number of months. The payment never changes — but what it is made of does.
Why early payments barely move the balance
Interest is charged on what you still owe, so at the start almost the whole payment is interest and only a sliver touches the principal. Look at the table: in month one on a 30-year loan, the split is brutal. It flips slowly, and only near the end is most of your payment actually buying the house. This is also why overpaying early is so powerful — every extra dollar goes straight at the principal and removes all the future interest that dollar would have carried.
What this number does not include
This is principal and interest only — the loan itself. Your real monthly cost also carries property tax, home insurance, any mortgage insurance if you put down less than 20%, and HOA or condo fees. Budget those separately; they are often a large share of the payment.
Informational and educational result. Not a substitute for professional advice.
Frequently asked questions
Sources
- Consumer Financial Protection Bureau (CFPB) — Understand loan options and mortgage costs
- Standard amortization formula for fixed-rate loans