Mortgage basics
A mortgage is a secured loan used to purchase real estate. The property acts as collateral, and the loan is usually repaid through scheduled monthly payments. This mortgage payment calculator estimates principal and interest for a fixed-rate loan. It does not include property taxes, homeowners insurance, HOA fees, PMI, lender fees, or closing costs.
The monthly mortgage payment is often the first number people compare, but it is not the only number that matters. A lower monthly payment can improve monthly cash flow, while a shorter term can reduce the total interest paid and build equity faster. This page is designed to make those tradeoffs visible by showing payment, total interest, total paid, charts, and a full amortization schedule.
For a broader overview of how principal and interest work, you can search Google for fixed-rate mortgage principal and interest explained.
Inputs
The quality of a mortgage estimate depends on the assumptions entered. Try changing one input at a time so you can tell whether the payment changed because of price, down payment, interest rate, or term length. This is especially useful when comparing lender quotes or deciding whether a larger down payment is worth using.
- Home price: the purchase price before subtracting the down payment.
- Annual interest rate: the nominal yearly mortgage rate. The calculator converts it into a monthly rate.
- Loan term: duration in years, such as 15, 20, or 30 years. Longer terms usually lower the payment but increase interest.
- Down payment: upfront cash applied to the purchase. It reduces financed principal and may affect loan-to-value outside this simplified model.
If you are still deciding how much house may fit your budget, compare this page with a home affordability estimate and search Google for mortgage debt-to-income ratio and home affordability.
Formula
For a fixed-rate mortgage, the monthly principal-and-interest payment is based on the amortization formula. The calculation spreads the financed principal across the full loan term while charging interest on the remaining balance each month.
PV = home price - down payment
r = annual interest rate / 100 / 12
P = PV x r / (1 - (1 + r)^(-n))
Total interest = total paid - financed principal
When the rate is zero, the payment is simply financed principal divided by the number of payments. For positive rates, early payments contain more interest because the remaining balance is still high. Later payments shift toward principal as the balance falls. To explore how different rate environments affect borrowing costs, search Google for current mortgage interest rate trends 2026.
Cost factors
Mortgage cost is shaped by several linked factors. A small rate change can make a large difference on a long mortgage because the balance is repaid over many months. To see more amortization examples, search Google for mortgage amortization schedule principal interest example.
Interest rate
- Higher rates raise monthly payment and total interest.
- Rate changes often have a larger effect on long-term loans than short-term loans.
- Discount points, lender credits, and rate locks can change the actual cost of a quote outside this calculator.
Term length
- Longer terms lower monthly payment but usually increase total interest.
- Shorter terms usually build equity faster because more principal is paid each month.
- A 15-year mortgage may cost more per month than a 30-year mortgage, but the interest savings can be substantial.
Down payment
- Larger down payments reduce financed principal and can reduce total interest.
- A larger down payment may also affect loan-to-value, mortgage insurance, and lender terms outside this simplified model.
- Keeping some cash reserves may still be important even when a larger down payment lowers the mortgage payment.
| Loan term (years) | Interest rate (%) | Down payment ($) | Approximate monthly payment | Estimated total interest |
|---|---|---|---|---|
| 30 | 6.5 | 70,000 | $1,770 | $357,125 |
| 20 | 6.5 | 70,000 | $2,088 | $221,025 |
| 15 | 6.5 | 70,000 | $2,439 | $159,038 |
| 30 | 5.5 | 70,000 | $1,590 | $292,331 |
| 30 | 6.5 | 100,000 | $1,580 | $318,861 |
The table above illustrates how changing one variable at a time alters both the monthly payment and total interest for a $350,000 home price. Use the calculator's scenario comparison feature to test your own numbers.
Understanding amortization
An amortization schedule shows how every monthly mortgage payment is divided between interest and principal. At the beginning of the loan, interest usually takes a larger share because it is charged against a larger balance. Over time, the balance declines and more of each payment goes toward principal.
This shift is why total interest can look surprisingly high on long-term mortgages. The payment may stay fixed, but the interest-principal split changes every month. Reviewing the schedule can help you understand how quickly equity builds and how much interest remains at different points in the loan.
| Schedule item | What it shows | How to use it |
|---|---|---|
| Payment | The scheduled principal-and-interest amount. | Compare against monthly cash flow before adding escrow items. |
| Interest | The portion charged for borrowing during the period. | Shows why early payments reduce the balance slowly. |
| Principal | The portion that reduces the outstanding balance. | Tracks equity-building progress over time. |
| Remaining balance | The loan balance after each payment. | Useful when estimating refinance, payoff, or sale timing. |
| Year | Monthly payment | Interest portion in final month | Principal portion in final month | Remaining balance after year |
|---|---|---|---|---|
| 1 | $1,770 | $1,501 | $269 | $276,870 |
| 5 | $1,770 | $1,422 | $348 | $262,111 |
| 10 | $1,770 | $1,288 | $481 | $237,373 |
| 15 | $1,770 | $1,104 | $666 | $203,166 |
| 20 | $1,770 | $849 | $921 | $155,863 |
| 25 | $1,770 | $497 | $1,273 | $90,452 |
The amortization table above demonstrates how the interest-to-principal ratio shifts over the life of a 30-year loan. Notice that in year 1 the interest portion is nearly six times the principal portion, but by year 25 the situation reverses completely. This is why making extra principal payments early in the loan term can produce significant interest savings.
Mortgage payment and affordability
This calculator focuses on principal and interest, so it is best used as the financing layer of a housing budget. A real monthly housing payment may also include property tax, homeowners insurance, private mortgage insurance, HOA dues, utilities, maintenance, and local fees.
When you compare affordability, look beyond the mortgage payment itself. A payment that seems comfortable before escrow may become tight after taxes and insurance. A payment that fits today may also be affected by future income changes, emergency savings, repairs, and other debt obligations. For a deeper look at how lenders evaluate your financial profile, search Google for how mortgage lenders calculate borrowing capacity and debt-to-income ratio.
Comparison table
Use scenarios to compare the same home price with different down payments, rates, and terms. The most useful comparison is rarely one number by itself; monthly payment, total interest, and remaining balance all tell a different part of the story.
| Question | Metric to compare | Why it matters |
|---|---|---|
| Can I handle the monthly cost? | Monthly payment | Shows the principal and interest cash flow before taxes and insurance. |
| How expensive is the mortgage? | Total interest | Shows the long-term financing cost beyond principal. |
| How much am I financing? | Financed principal | Shows the loan balance after down payment. |
| How quickly does the balance fall? | Amortization schedule | Shows principal, interest, and remaining balance each month. |
For example, compare a 30-year term with a 15-year term at the same home price and rate. The shorter term may raise the monthly payment, but it can reduce total interest and shorten the time needed to own the home free and clear. Compare scenarios before focusing on a single monthly payment number.
Mortgage types overview
Not all mortgages are the same. While this calculator models a fixed-rate loan, homebuyers may also encounter adjustable-rate mortgages (ARMs), FHA loans, VA loans, USDA loans, and jumbo loans. Each type has different qualification requirements, insurance rules, and rate structures. Understanding the differences helps you choose a product that aligns with your financial situation and homeownership goals.
| Mortgage type | Rate structure | Down payment requirement | Best suited for |
|---|---|---|---|
| Fixed-rate conventional | Rate stays the same for the full term | 3% to 20% depending on lender | Buyers who plan to stay long-term and want predictable payments |
| Adjustable-rate (ARM) | Fixed for an initial period, then adjusts periodically | 5% to 20% | Buyers who plan to sell or refinance before the rate adjusts |
| FHA loan | Fixed or adjustable | As low as 3.5% | First-time buyers with lower credit scores or limited savings |
| VA loan | Fixed or adjustable | 0% (no down payment required) | Eligible veterans, active-duty service members, and surviving spouses |
| USDA loan | Fixed | 0% (no down payment required) | Buyers in eligible rural and suburban areas with moderate income |
| Jumbo loan | Fixed or adjustable | 10% to 30% | Buyers financing a home above the conforming loan limit |
The table above summarizes the main mortgage categories available to homebuyers. Each type serves a different purpose, and the right choice depends on your credit profile, income stability, down payment savings, and how long you expect to stay in the home.
What this calculator does not include
This tool models a fixed-rate principal-and-interest mortgage. It does not include escrow items such as property tax and homeowners insurance, nor does it model PMI, HOA dues, adjustable-rate changes, points, lender credits, refinance costs, prepayment penalties, extra payments, biweekly payment plans, or closing costs.
Use this result as a clean financing baseline, then compare it with lender disclosures and local housing costs. If a lender quote is different from this estimate, the difference often comes from taxes, insurance, fees, rate lock details, points, or other contract terms.