Monthly Payment & Amortization
Last reviewed: May 2026
Calculate the monthly mortgage payment for any loan amount, rate, and term. The principal and interest (P&I) payment is just the beginning — add property taxes, homeowner’s insurance, and PMI for the true monthly housing cost (PITI). Understanding all four components prevents the costly surprise of buying a home you can technically finance but cannot comfortably afford.1
| Metric | 30-Year at 7% | 15-Year at 6.5% | Difference |
|---|---|---|---|
| Monthly P&I ($300K) | $1,996 | $2,613 | +$617/mo |
| Total interest paid | $418,527 | $170,388 | −$248,139 |
| Total cost | $718,527 | $470,388 | −$248,139 |
| Component | Monthly | % of Total |
|---|---|---|
| Principal & Interest | $1,996 | 72% |
| Property tax | $417 | 15% |
| Homeowner’s insurance | $150 | 5% |
| PMI (if <20% down) | $208 | 8% |
| Total PITI | $2,771 | 100% |
The standard mortgage payment formula is M = P[r(1+r)^n] / [(1+r)^n - 1], where P is the principal, r is the monthly interest rate (annual rate divided by 12), and n is the total number of payments. For a $350,000 mortgage at 6.5% over 30 years: r = 0.065/12 = 0.005417, n = 360. M = 350,000 × [0.005417(1.005417)^360] / [(1.005417)^360 - 1] = $2,212/month for principal and interest. This formula produces a fixed payment where the proportion allocated to interest versus principal shifts over time — early payments are roughly 80% interest and 20% principal, while late payments reverse that ratio. The total cost of this mortgage: $2,212 × 360 = $796,320, meaning you pay $446,320 in interest — more than the home's original price.
The principal-and-interest payment from the formula above is only part of your total monthly housing cost. Most lenders require an escrow account that collects property taxes and homeowner's insurance monthly, then pays them when due. PITI (Principal, Interest, Taxes, Insurance) is the complete picture: on a $350,000 home with $4,200/year property tax and $1,800/year insurance, add $500/month to the $2,212 P&I for a total of $2,712. If your down payment is less than 20%, add PMI (Private Mortgage Insurance) at 0.5-1% of the loan amount annually — roughly $146-292/month on $350,000. HOA dues add another $100-500+/month for condos and planned communities. The gap between the "mortgage payment" from a calculator and total housing cost catches many first-time buyers off guard.
A 30-year fixed mortgage's payment stays constant, but the allocation between interest and principal changes dramatically. In month 1 of a $350,000 loan at 6.5%, your $2,212 payment splits: $1,896 interest and $316 principal. After 10 years (month 120), the same $2,212 splits: $1,485 interest and $727 principal. After 20 years (month 240): $856 interest and $1,356 principal. The tipping point — where more goes to principal than interest — doesn't arrive until roughly year 19 on a 30-year mortgage at 6.5%. This front-loaded interest structure is why making extra principal payments early in the loan term has an outsized impact: an extra $200/month starting in year 1 saves approximately $95,000 in interest and pays off the loan 6 years early, while the same extra payment starting in year 15 saves only about $25,000.
A 15-year mortgage typically carries an interest rate 0.5-0.75% lower than a 30-year and builds equity dramatically faster. On $350,000: a 30-year at 6.5% costs $2,212/month with $446,320 total interest. A 15-year at 5.875% costs $2,936/month with $178,480 total interest — saving $267,840 in interest for an additional $724/month. The 15-year builds equity roughly 4x faster in the first decade. The trade-off is cash flow flexibility: the higher required payment on a 15-year leaves less monthly cushion for emergencies, job disruptions, or other investments. A middle-ground strategy: take the 30-year mortgage but make payments as if it were a 15-year. This preserves the option to drop back to the lower required payment during financial stress while capturing most of the interest savings during normal times.
Small rate differences produce large payment and total-cost changes over a mortgage's life. On a $400,000 30-year mortgage: at 5.5%, the payment is $2,271 with $417,614 total interest. At 6.5%, $2,528 with $510,177 interest. At 7.5%, $2,797 with $606,852 interest. Each 1% increase adds roughly $250-270/month and $95,000-97,000 in total interest on a $400,000 loan. Rate buydowns (paying points upfront to reduce the rate) cost 1% of the loan amount per 0.25% rate reduction: on $400,000, paying $4,000 to drop from 6.5% to 6.25% saves $65/month — a breakeven of 61 months (5 years). If you'll keep the mortgage longer than 5 years, the buydown saves money; if you'll refinance or move sooner, the upfront cost is wasted. Rate lock timing also matters: locking a rate when you're pre-approved protects against increases during your home search, typically for 30-90 days.
The standard mortgage payment formula is M = P[r(1+r)^n] / [(1+r)^n - 1], where P is the principal, r is the monthly interest rate (annual rate divided by 12), and n is the total number of payments. For a $350,000 mortgage at 6.5% over 30 years: r = 0.065/12 = 0.005417, n = 360. M = 350,000 × [0.005417(1.005417)^360] / [(1.005417)^360 - 1] = $2,212/month for principal and interest. This formula produces a fixed payment where the proportion allocated to interest versus principal shifts over time — early payments are roughly 80% interest and 20% principal, while late payments reverse that ratio. The total cost of this mortgage: $2,212 × 360 = $796,320, meaning you pay $446,320 in interest — more than the home's original price.
The principal-and-interest payment from the formula above is only part of your total monthly housing cost. Most lenders require an escrow account that collects property taxes and homeowner's insurance monthly, then pays them when due. PITI (Principal, Interest, Taxes, Insurance) is the complete picture: on a $350,000 home with $4,200/year property tax and $1,800/year insurance, add $500/month to the $2,212 P&I for a total of $2,712. If your down payment is less than 20%, add PMI (Private Mortgage Insurance) at 0.5-1% of the loan amount annually — roughly $146-292/month on $350,000. HOA dues add another $100-500+/month for condos and planned communities. The gap between the "mortgage payment" from a calculator and total housing cost catches many first-time buyers off guard.
A 30-year fixed mortgage's payment stays constant, but the allocation between interest and principal changes dramatically. In month 1 of a $350,000 loan at 6.5%, your $2,212 payment splits: $1,896 interest and $316 principal. After 10 years (month 120), the same $2,212 splits: $1,485 interest and $727 principal. After 20 years (month 240): $856 interest and $1,356 principal. The tipping point — where more goes to principal than interest — doesn't arrive until roughly year 19 on a 30-year mortgage at 6.5%. This front-loaded interest structure is why making extra principal payments early in the loan term has an outsized impact: an extra $200/month starting in year 1 saves approximately $95,000 in interest and pays off the loan 6 years early, while the same extra payment starting in year 15 saves only about $25,000.
A 15-year mortgage typically carries an interest rate 0.5-0.75% lower than a 30-year and builds equity dramatically faster. On $350,000: a 30-year at 6.5% costs $2,212/month with $446,320 total interest. A 15-year at 5.875% costs $2,936/month with $178,480 total interest — saving $267,840 in interest for an additional $724/month. The 15-year builds equity roughly 4x faster in the first decade. The trade-off is cash flow flexibility: the higher required payment on a 15-year leaves less monthly cushion for emergencies, job disruptions, or other investments. A middle-ground strategy: take the 30-year mortgage but make payments as if it were a 15-year. This preserves the option to drop back to the lower required payment during financial stress while capturing most of the interest savings during normal times.
Small rate differences produce large payment and total-cost changes over a mortgage's life. On a $400,000 30-year mortgage: at 5.5%, the payment is $2,271 with $417,614 total interest. At 6.5%, $2,528 with $510,177 interest. At 7.5%, $2,797 with $606,852 interest. Each 1% increase adds roughly $250-270/month and $95,000-97,000 in total interest on a $400,000 loan. Rate buydowns (paying points upfront to reduce the rate) cost 1% of the loan amount per 0.25% rate reduction: on $400,000, paying $4,000 to drop from 6.5% to 6.25% saves $65/month — a breakeven of 61 months (5 years). If you'll keep the mortgage longer than 5 years, the buydown saves money; if you'll refinance or move sooner, the upfront cost is wasted. Rate lock timing also matters: locking a rate when you're pre-approved protects against increases during your home search, typically for 30-90 days.
The standard mortgage payment formula is M = P[r(1+r)^n] / [(1+r)^n - 1], where P is the principal, r is the monthly interest rate (annual rate divided by 12), and n is the total number of payments. For a $350,000 mortgage at 6.5% over 30 years: r = 0.065/12 = 0.005417, n = 360. M = 350,000 × [0.005417(1.005417)^360] / [(1.005417)^360 - 1] = $2,212/month for principal and interest. This formula produces a fixed payment where the proportion allocated to interest versus principal shifts over time — early payments are roughly 80% interest and 20% principal, while late payments reverse that ratio. The total cost of this mortgage: $2,212 × 360 = $796,320, meaning you pay $446,320 in interest — more than the home's original price.
The principal-and-interest payment from the formula above is only part of your total monthly housing cost. Most lenders require an escrow account that collects property taxes and homeowner's insurance monthly, then pays them when due. PITI (Principal, Interest, Taxes, Insurance) is the complete picture: on a $350,000 home with $4,200/year property tax and $1,800/year insurance, add $500/month to the $2,212 P&I for a total of $2,712. If your down payment is less than 20%, add PMI (Private Mortgage Insurance) at 0.5-1% of the loan amount annually — roughly $146-292/month on $350,000. HOA dues add another $100-500+/month for condos and planned communities. The gap between the "mortgage payment" from a calculator and total housing cost catches many first-time buyers off guard.
A 30-year fixed mortgage's payment stays constant, but the allocation between interest and principal changes dramatically. In month 1 of a $350,000 loan at 6.5%, your $2,212 payment splits: $1,896 interest and $316 principal. After 10 years (month 120), the same $2,212 splits: $1,485 interest and $727 principal. After 20 years (month 240): $856 interest and $1,356 principal. The tipping point — where more goes to principal than interest — doesn't arrive until roughly year 19 on a 30-year mortgage at 6.5%. This front-loaded interest structure is why making extra principal payments early in the loan term has an outsized impact: an extra $200/month starting in year 1 saves approximately $95,000 in interest and pays off the loan 6 years early, while the same extra payment starting in year 15 saves only about $25,000.
A 15-year mortgage typically carries an interest rate 0.5-0.75% lower than a 30-year and builds equity dramatically faster. On $350,000: a 30-year at 6.5% costs $2,212/month with $446,320 total interest. A 15-year at 5.875% costs $2,936/month with $178,480 total interest — saving $267,840 in interest for an additional $724/month. The 15-year builds equity roughly 4x faster in the first decade. The trade-off is cash flow flexibility: the higher required payment on a 15-year leaves less monthly cushion for emergencies, job disruptions, or other investments. A middle-ground strategy: take the 30-year mortgage but make payments as if it were a 15-year. This preserves the option to drop back to the lower required payment during financial stress while capturing most of the interest savings during normal times.
Small rate differences produce large payment and total-cost changes over a mortgage's life. On a $400,000 30-year mortgage: at 5.5%, the payment is $2,271 with $417,614 total interest. At 6.5%, $2,528 with $510,177 interest. At 7.5%, $2,797 with $606,852 interest. Each 1% increase adds roughly $250-270/month and $95,000-97,000 in total interest on a $400,000 loan. Rate buydowns (paying points upfront to reduce the rate) cost 1% of the loan amount per 0.25% rate reduction: on $400,000, paying $4,000 to drop from 6.5% to 6.25% saves $65/month — a breakeven of 61 months (5 years). If you'll keep the mortgage longer than 5 years, the buydown saves money; if you'll refinance or move sooner, the upfront cost is wasted. Rate lock timing also matters: locking a rate when you're pre-approved protects against increases during your home search, typically for 30-90 days.
The standard mortgage payment formula is M = P[r(1+r)^n] / [(1+r)^n - 1], where P is the principal, r is the monthly interest rate (annual rate divided by 12), and n is the total number of payments. For a $350,000 mortgage at 6.5% over 30 years: r = 0.065/12 = 0.005417, n = 360. M = 350,000 × [0.005417(1.005417)^360] / [(1.005417)^360 - 1] = $2,212/month for principal and interest. This formula produces a fixed payment where the proportion allocated to interest versus principal shifts over time — early payments are roughly 80% interest and 20% principal, while late payments reverse that ratio. The total cost of this mortgage: $2,212 × 360 = $796,320, meaning you pay $446,320 in interest — more than the home's original price.
The principal-and-interest payment from the formula above is only part of your total monthly housing cost. Most lenders require an escrow account that collects property taxes and homeowner's insurance monthly, then pays them when due. PITI (Principal, Interest, Taxes, Insurance) is the complete picture: on a $350,000 home with $4,200/year property tax and $1,800/year insurance, add $500/month to the $2,212 P&I for a total of $2,712. If your down payment is less than 20%, add PMI (Private Mortgage Insurance) at 0.5-1% of the loan amount annually — roughly $146-292/month on $350,000. HOA dues add another $100-500+/month for condos and planned communities. The gap between the "mortgage payment" from a calculator and total housing cost catches many first-time buyers off guard.
A 30-year fixed mortgage's payment stays constant, but the allocation between interest and principal changes dramatically. In month 1 of a $350,000 loan at 6.5%, your $2,212 payment splits: $1,896 interest and $316 principal. After 10 years (month 120), the same $2,212 splits: $1,485 interest and $727 principal. After 20 years (month 240): $856 interest and $1,356 principal. The tipping point — where more goes to principal than interest — doesn't arrive until roughly year 19 on a 30-year mortgage at 6.5%. This front-loaded interest structure is why making extra principal payments early in the loan term has an outsized impact: an extra $200/month starting in year 1 saves approximately $95,000 in interest and pays off the loan 6 years early, while the same extra payment starting in year 15 saves only about $25,000.
A 15-year mortgage typically carries an interest rate 0.5-0.75% lower than a 30-year and builds equity dramatically faster. On $350,000: a 30-year at 6.5% costs $2,212/month with $446,320 total interest. A 15-year at 5.875% costs $2,936/month with $178,480 total interest — saving $267,840 in interest for an additional $724/month. The 15-year builds equity roughly 4x faster in the first decade. The trade-off is cash flow flexibility: the higher required payment on a 15-year leaves less monthly cushion for emergencies, job disruptions, or other investments. A middle-ground strategy: take the 30-year mortgage but make payments as if it were a 15-year. This preserves the option to drop back to the lower required payment during financial stress while capturing most of the interest savings during normal times.
Small rate differences produce large payment and total-cost changes over a mortgage's life. On a $400,000 30-year mortgage: at 5.5%, the payment is $2,271 with $417,614 total interest. At 6.5%, $2,528 with $510,177 interest. At 7.5%, $2,797 with $606,852 interest. Each 1% increase adds roughly $250-270/month and $95,000-97,000 in total interest on a $400,000 loan. Rate buydowns (paying points upfront to reduce the rate) cost 1% of the loan amount per 0.25% rate reduction: on $400,000, paying $4,000 to drop from 6.5% to 6.25% saves $65/month — a breakeven of 61 months (5 years). If you'll keep the mortgage longer than 5 years, the buydown saves money; if you'll refinance or move sooner, the upfront cost is wasted. Rate lock timing also matters: locking a rate when you're pre-approved protects against increases during your home search, typically for 30-90 days.
The standard mortgage payment formula is M = P[r(1+r)^n] / [(1+r)^n - 1], where P is the principal, r is the monthly interest rate (annual rate divided by 12), and n is the total number of payments. For a $350,000 mortgage at 6.5% over 30 years: r = 0.065/12 = 0.005417, n = 360. M = 350,000 × [0.005417(1.005417)^360] / [(1.005417)^360 - 1] = $2,212/month for principal and interest. This formula produces a fixed payment where the proportion allocated to interest versus principal shifts over time — early payments are roughly 80% interest and 20% principal, while late payments reverse that ratio. The total cost of this mortgage: $2,212 × 360 = $796,320, meaning you pay $446,320 in interest — more than the home's original price.
The principal-and-interest payment from the formula above is only part of your total monthly housing cost. Most lenders require an escrow account that collects property taxes and homeowner's insurance monthly, then pays them when due. PITI (Principal, Interest, Taxes, Insurance) is the complete picture: on a $350,000 home with $4,200/year property tax and $1,800/year insurance, add $500/month to the $2,212 P&I for a total of $2,712. If your down payment is less than 20%, add PMI (Private Mortgage Insurance) at 0.5-1% of the loan amount annually — roughly $146-292/month on $350,000. HOA dues add another $100-500+/month for condos and planned communities. The gap between the "mortgage payment" from a calculator and total housing cost catches many first-time buyers off guard.
A 30-year fixed mortgage's payment stays constant, but the allocation between interest and principal changes dramatically. In month 1 of a $350,000 loan at 6.5%, your $2,212 payment splits: $1,896 interest and $316 principal. After 10 years (month 120), the same $2,212 splits: $1,485 interest and $727 principal. After 20 years (month 240): $856 interest and $1,356 principal. The tipping point — where more goes to principal than interest — doesn't arrive until roughly year 19 on a 30-year mortgage at 6.5%. This front-loaded interest structure is why making extra principal payments early in the loan term has an outsized impact: an extra $200/month starting in year 1 saves approximately $95,000 in interest and pays off the loan 6 years early, while the same extra payment starting in year 15 saves only about $25,000.
A 15-year mortgage typically carries an interest rate 0.5-0.75% lower than a 30-year and builds equity dramatically faster. On $350,000: a 30-year at 6.5% costs $2,212/month with $446,320 total interest. A 15-year at 5.875% costs $2,936/month with $178,480 total interest — saving $267,840 in interest for an additional $724/month. The 15-year builds equity roughly 4x faster in the first decade. The trade-off is cash flow flexibility: the higher required payment on a 15-year leaves less monthly cushion for emergencies, job disruptions, or other investments. A middle-ground strategy: take the 30-year mortgage but make payments as if it were a 15-year. This preserves the option to drop back to the lower required payment during financial stress while capturing most of the interest savings during normal times.
Small rate differences produce large payment and total-cost changes over a mortgage's life. On a $400,000 30-year mortgage: at 5.5%, the payment is $2,271 with $417,614 total interest. At 6.5%, $2,528 with $510,177 interest. At 7.5%, $2,797 with $606,852 interest. Each 1% increase adds roughly $250-270/month and $95,000-97,000 in total interest on a $400,000 loan. Rate buydowns (paying points upfront to reduce the rate) cost 1% of the loan amount per 0.25% rate reduction: on $400,000, paying $4,000 to drop from 6.5% to 6.25% saves $65/month — a breakeven of 61 months (5 years). If you'll keep the mortgage longer than 5 years, the buydown saves money; if you'll refinance or move sooner, the upfront cost is wasted. Rate lock timing also matters: locking a rate when you're pre-approved protects against increases during your home search, typically for 30-90 days.
→ Don't forget PITI. P&I is only 70–75% of your actual housing cost.
→ 15-year saves massively. But only if the higher payment fits your budget.
→ Extra payments help. Even $100/mo extra on a 30-year saves years and tens of thousands.
→ Shop multiple lenders. A 0.25% rate difference = thousands over the life of the loan.
See also: Home Affordability · Down Payment · Extra Payment · Interest Rate