Mortgage Calculator

Using the calculator is straightforward. You'll need a few key numbers handy before you start.

• Home price: The total purchase price of the property you're considering.
• Down payment: The amount you plan to pay upfront, either as a dollar amount or a percentage of the home price.
• Loan term: How long you'll take to repay the loan, typically 15 or 30 years.
• Interest rate: The annual rate your lender quotes you. If you haven't locked in a rate yet, use a current average as a starting point.
• Property taxes and insurance (optional): Adding these gives you a more realistic monthly cost, since most lenders roll them into your payment through an escrow account.

Once you've entered those values, hit calculate and you'll see your estimated monthly payment broken down into principal, interest, and any additional costs you included. Try adjusting the down payment or loan term to see how those changes affect what you owe each month. It's a good way to test different scenarios before you commit to anything.

The math behind a fixed-rate mortgage payment is actually pretty consistent. Lenders use a standard formula to figure out what you owe each month based on your loan balance, interest rate, and loan term.

The formula looks like this:

M = P [ r(1+r)^n ] / [ (1+r)^n - 1 ]

Here's what each variable means:

• M = your monthly mortgage payment
• P = the principal loan amount (home price minus your down payment)
• r = your monthly interest rate (annual rate divided by 12)
• n = the total number of payments (loan term in years multiplied by 12)

So if you borrow $300,000 at a 7% annual interest rate over 30 years, your monthly rate is 0.07 / 12, which equals about 0.00583, and your number of payments is 360. Running those numbers through the formula gives you a monthly principal and interest payment of roughly $1,996. The formula itself doesn't change; only the inputs do. That's why even small shifts in your interest rate or loan term can move your payment by hundreds of dollars.

Your monthly mortgage payment is rarely just one thing. It's usually made up of several components, and understanding each one helps you see exactly where your money is going.

• Principal: This is the portion that actually reduces your loan balance. In the early years of your loan, this is a smaller slice of your payment than you might expect.
• Interest: The cost of borrowing money. Early in your loan term, interest makes up the bulk of each payment. Over time, as your balance drops, the interest portion shrinks.
• Property taxes: Most lenders collect a monthly portion through escrow and pay your tax bill on your behalf when it comes due. The amount varies significantly by location.
• Homeowner's insurance: Required by virtually every lender, this protects the property against damage. It's also typically collected monthly through escrow.
• Private mortgage insurance (PMI): If your down payment is less than 20% of the home's value, your lender will likely require PMI. It protects the lender, not you, and adds to your monthly cost until you've built enough equity to cancel it.

The principal and interest portion stays fixed for the life of a fixed-rate loan, but your taxes and insurance can go up over time. That's why your payment might creep up slightly even if your rate never changes.

An amortization schedule is a full table showing every single payment you'll make over the life of your loan, broken down into principal and interest for each month. It sounds dry, but looking at one can be pretty eye-opening.

In the early months, most of your payment goes toward interest. On a 30-year, $300,000 loan at 7%, your very first payment might send around $1,750 to interest and only about $246 toward your actual balance. By the final years of the loan, that ratio flips completely.

A few things worth knowing about amortization:

• Your total interest paid over 30 years on that same loan would be well over $400,000 on top of the original $300,000 borrowed. The long-term cost of a mortgage is much higher than the sticker price of the home.
• Making extra payments toward principal early in the loan has an outsized effect because it reduces the balance on which future interest is calculated.
• Refinancing resets your amortization schedule, which is why switching to a lower rate doesn't always save as much as it looks like it should on paper.

Most mortgage calculators can generate a basic amortization table for you. It's worth reviewing before you finalize any loan decision.

Interest rate is probably the single most powerful lever in the whole mortgage equation. Even a difference of half a percent can add up to tens of thousands of dollars over the life of a 30-year loan.

Here's a quick look at how different rates affect the monthly principal and interest payment on a $350,000 loan over 30 years:

That's a swing of roughly $460 per month between the lowest and highest rate in this example. Over 30 years, that's more than $160,000 in additional interest. Getting even a slightly better rate is worth the effort of shopping multiple lenders and improving your credit score before you apply.

Your rate is determined by a mix of factors: your credit score, debt-to-income ratio, loan size, down payment, and what's happening in the broader economy. You can't control the market, but you can control how well-prepared your financial profile is when you apply.

The more you put down upfront, the less you borrow, and the lower your monthly payment. That part's obvious. But the down payment also affects your loan in a few other ways that are worth thinking through.

Putting down at least 20% of the purchase price eliminates the need for PMI, which can easily run $100 to $200 or more per month depending on your loan amount and credit profile. That's real money you'd save every single month. It also means a smaller principal balance, which means less interest accumulates over time.

On a $400,000 home, here's how different down payment amounts change the loan:

That said, draining your savings to hit 20% isn't always the right call. If it leaves you with no emergency fund, the financial risk of being cash-poor can outweigh the benefit of avoiding PMI. There's a balance to strike, and it depends on your personal situation.

When you're choosing a mortgage, one of the first decisions you'll face is whether to go with a fixed rate or an adjustable rate. Both have legitimate use cases, and neither is automatically better.

Fixed-rate mortgages lock in your interest rate for the entire loan term. Your principal and interest payment never changes. That predictability is valuable, especially if you plan to stay in the home long-term or if rates are relatively low when you buy.

Adjustable-rate mortgages (ARMs) start with a fixed rate for an initial period, usually 5, 7, or 10 years, then adjust periodically based on a market index. A 5/1 ARM, for example, holds its rate for five years and then adjusts once a year after that. The initial rate is typically lower than a comparable fixed rate, which can make the monthly payment more affordable upfront.

ARMs can make sense if you're confident you'll sell or refinance before the adjustable period kicks in. But if there's any chance you'll stay longer than expected, the rate risk is real. Rates can adjust upward by several percentage points, and your payment could jump substantially. Most buyers in uncertain situations are better off with the stability of a fixed rate.

There are concrete steps you can take to lower what you pay, both upfront and over the life of the loan. Some require planning ahead; others you can act on right now.

• Improve your credit score before applying. Even bumping your score from 680 to 740 can qualify you for a meaningfully lower rate. Pay down balances, dispute any errors on your report, and avoid opening new credit accounts in the months before you apply.
• Shop multiple lenders. Rates and fees vary more than most people realize. Getting quotes from at least three to five lenders, including credit unions and online lenders, can save you thousands. Don't just look at the rate; compare the APR and closing costs too.
• Consider buying mortgage points. Paying discount points upfront lowers your interest rate for the life of the loan. Whether it's worth it depends on how long you plan to stay in the home, but if you're in it for the long haul, it can pay off.
• Make extra principal payments. Even one additional payment per year can shave years off a 30-year loan and save a significant amount in interest. Some people set up biweekly payments instead of monthly, which results in 26 half-payments (equivalent to 13 full payments) per year.
• Avoid extending your loan term when refinancing. Refinancing into a lower rate can save money, but restarting the clock on a new 30-year loan when you're already 10 years in often costs more in interest than it saves. Consider a shorter term or make extra payments to compensate.
• Cancel PMI as soon as you're eligible. Once your loan balance drops to 80% of the home's original appraised value, you can typically request PMI cancellation. Your lender won't always do it automatically, so you may need to ask.

None of these are complicated, but they do require attention and some advance planning. Small decisions made early in the process can have a surprisingly large impact on your total cost over time.