Compute your monthly mortgage payment with full PITI (principal + interest + tax + insurance), optional PMI and HOA, and see the amortization schedule.
Monthly payment (PITI)
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Loan amount
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Total interest over life of loan
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Total paid (P + I)
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Loan-to-value (LTV)
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Amortization snapshot (every 5 years)
| Year | Balance | Principal paid YTD | Interest paid YTD |
|---|
Worked example
Take a $450,000 home with $90,000 down, a 6.5% fixed rate, and a 30 year term, plus $5,400 a year in property tax and $1,800 a year in homeowners insurance. The loan amount is $450,000 minus $90,000, or $360,000, which is an 80% loan-to-value ratio, the point at which most conventional lenders stop requiring PMI. The monthly principal and interest, using the standard amortization formula at a 0.5417% monthly rate over 360 payments, is $2,275.44. Property tax and insurance add $7,200 a year, or $600 a month, so the full monthly payment is $2,875.44. Over the life of the loan you make 360 payments of $2,275.44, which totals $819,160. Since you only borrowed $360,000, the remaining $459,160 is interest. In the early years almost all of each payment is interest, and the principal share climbs as the balance shrinks.
| Item | Amount |
|---|---|
| Loan amount | $360,000 |
| Monthly principal + interest | $2,275.44 |
| Tax + insurance per month | $600.00 |
| Total monthly payment | $2,875.44 |
| Total interest over 30 years | $459,160 |
| Total of P&I payments | $819,160 |
How it is calculated
A fixed-rate mortgage is a fully amortizing loan, so every monthly payment is identical and is split between interest on the outstanding balance and principal that pays the loan down. The monthly principal and interest is the loan amount times the monthly rate times one plus the monthly rate raised to the number of payments, divided by that same term minus one. The monthly rate is the annual rate divided by 12, and the number of payments is the term in years times 12. Because interest is charged on the remaining balance, the interest portion is largest at the start and falls every month while the principal portion rises, which is the amortization schedule shown above. The total payment also folds in escrow items, property tax and insurance divided by 12, plus any PMI and HOA dues. Lenders typically require PMI until your loan-to-value ratio drops to 80%.