Mortgage calculator
Purchase price, down payment, rate, and term into a monthly payment, the lifetime interest, and the balance curve as it pays down.
Worked example — Monthly payment (principal and interest): $2,528.27. $400,000 loan at 6.5% over 30 years, $100,000 down on a $500,000 purchase
The home and down payment
The loan
Advanced options 2
Monthly payment per $100,000 borrowed, by rate and term
Principal-and-interest payment on a $100,000 loan at each rate, so it scales to any loan size: multiply the cell by your loan amount in hundreds of thousands. Every value comes from the same closed-form annuity formula the calculator above runs.
| Rate | 15-year | 30-year |
|---|---|---|
| 5% | $790.79 | $536.82 |
| 5.5% | $817.08 | $567.79 |
| 6% | $843.86 | $599.55 |
| 6.5% | $871.11 | $632.07 |
| 7% | $898.83 | $665.30 |
| 7.5% | $927.01 | $699.21 |
| 8% | $955.65 | $733.76 |
How much interest will I pay over the life of a mortgage?
On the default scenario above, a $400,000 loan at 6.5% over 30 years costs $510,178 in interest by the time it is paid off, more than the loan itself. The total paid over the term, principal and interest together, is $910,178. Interest is front-loaded: the first year's payments are mostly interest, and the split reverses only gradually as the balance falls, which is what the amortization chart above shows.
15-year vs 30-year mortgage: payment and total interest
Same $400,000 loan at 6.5%, two terms. The 30-year has the lower monthly payment; the 15-year has dramatically lower total interest, because the balance is retired in half the time and has half as long to accrue interest against.
| Term | Monthly payment | Total interest | Total paid |
|---|---|---|---|
| 15-year | $3,484.43 | $227,197 | $627,197 |
| 30-year | $2,528.27 | $510,178 | $910,178 |
The 30-year payment is $956.16 a month lower, but it costs $282,981 more in interest over the life of the loan. That trade is the whole decision: lower required payment against a much larger lifetime cost.
The next question after this one
U.S. rent vs buy calculatorCalculatorThe payment is affordable. Whether buying beats renting is a different question, and this one discounts both streams.Open nextOther questions
All 130 calculatorsHow JMM sources and checks its numbersWhat stays free, and what early access would add
What Pro adds here
Refinance comparisons, biweekly payment effects, extra-principal impact, and mortgage-versus-invest math are Pro features. The launch list sends one email at launch.