Mortgage Payment Calculator

How Mortgage Amortization Works

Every mortgage payment you make is split between principal (reducing your loan balance) and interest (the cost of borrowing). The exact split is determined by the standard amortization formula that lenders use worldwide:

M = P × [r(1+r)ⁿ] / [(1+r)ⁿ − 1]

Where M is your monthly payment, P is the loan principal, r is the monthly interest rate (annual rate divided by 12), and n is the total number of monthly payments. For a $320,000 loan at 6.75% over 30 years, this formula yields a monthly P&I payment of approximately $2,076.

Here's what surprises most homeowners: in the early years of your loan, the vast majority of each payment goes toward interest, not principal. On that $320,000 loan, your first payment allocates roughly $1,800 to interest and only $276 to principal. That means only 13% of your initial payment actually reduces what you owe. This ratio shifts gradually over time — by year 15, approximately half of each payment goes to principal, and by year 25, over 80% of each payment reduces your balance.

This shifting principal-to-interest ratio is what builds your home equity over time. Equity is the difference between your home's value and your remaining loan balance. In the early years, equity builds slowly because so little of each payment reduces principal. This is precisely why strategies like extra payments are so powerful early in the loan — each additional dollar goes entirely toward principal, bypassing the interest-heavy early years.

The difference between a 30-year and 15-year mortgage is dramatic. On that $320,000 loan at 6.75%, a 30-year term means you'll pay approximately $427,000 in total interest — more than the loan itself. Switch to a 15-year term at a typical rate of 6.14%, and total interest drops to roughly $173,000 — saving you over $254,000. The tradeoff is a significantly higher monthly payment (around $2,720/month vs. $2,076), but you build equity far faster and own your home outright in half the time.

Read our full guide on calculating mortgage payments →

Fixed-Rate vs Adjustable-Rate Mortgages (ARM)

Choosing between a fixed-rate mortgage and an adjustable-rate mortgage (ARM) is one of the most consequential decisions you'll make when financing a home. Each structure has distinct advantages depending on your financial situation, how long you plan to stay, and your risk tolerance.

Fixed-rate mortgages offer complete predictability. Your interest rate — and therefore your principal and interest payment — never changes for the entire life of the loan, whether that's 15, 20, or 30 years. In 2026, with 30-year fixed rates hovering around 6.75%–7.00%, you lock in certainty. Even if inflation rises or the economy shifts, your payment stays the same. This stability makes budgeting straightforward and eliminates the risk of payment shock. The downside is that fixed rates are typically 0.5%–1.0% higher than the initial rate on an ARM, meaning you pay a premium for that certainty.

Adjustable-rate mortgages feature a lower introductory rate for a fixed initial period, after which the rate adjusts periodically based on a market index plus a margin. The most common structures are the 5/1 ARM (fixed for 5 years, then adjusts annually) and the 7/1 ARM (fixed for 7 years, then adjusts annually). In 2026, a 5/1 ARM might offer an initial rate of 5.75%–6.25% compared to 6.75%+ for a 30-year fixed — saving you $200–$400/month in those initial years.

When do ARMs make sense? If you're confident you'll sell or refinance within 5–7 years — perhaps due to a planned relocation, career move, or home upgrade — an ARM lets you capture the lower initial rate without ever facing the adjustment. First-time buyers who expect their income to grow significantly may also benefit, as they can refinance into a fixed-rate before the adjustment period begins. However, if you plan to stay in your home long-term and value payment stability above all else, a fixed-rate mortgage remains the safer choice. The 2026 rate environment, with the Federal Reserve having paused rate cuts, makes fixed rates more competitive compared to ARMs than in previous years.

ARMs include rate caps that limit how much your rate can increase at each adjustment (typically 2% per adjustment) and over the life of the loan (typically 5%–6% above the initial rate). Always understand your ARM's cap structure before committing — a worst-case scenario calculation should still be affordable for your budget.

How to Save Thousands on Your Mortgage

Most homeowners don't realize that small changes to their payment strategy can save tens of thousands — or even hundreds of thousands — of dollars over the life of a mortgage. The key insight is that every extra dollar you pay goes directly to principal, reducing the balance that accrues interest for every remaining month of your loan.

Extra monthly payments: Even adding $100 per month to your mortgage payment on a $320,000 loan at 6.75% saves approximately $52,000 in interest and cuts 4.5 years off the loan. Bump that to $200/month extra, and you save over $88,000 and eliminate nearly 7 years of payments. The earlier you start making extra payments, the more you save, because you're reducing principal during the period when interest charges are highest. Think of it this way: $100/month extra in year 1 is far more valuable than $100/month extra in year 20, because the reduced principal compounds interest savings over the remaining decades.

Bi-weekly payments: This is the "set it and forget it" strategy. Instead of making one monthly payment, you pay half your P&I amount every two weeks. Because there are 52 weeks in a year, this results in 26 half-payments — equivalent to 13 full monthly payments per year instead of 12. That single extra payment each year, applied entirely to principal, can shave 4–6 years off a 30-year mortgage and save $40,000–$60,000 in interest on a typical loan. The best part: most people who get paid bi-weekly barely notice the difference in their budget.

Refinancing when rates drop: If current market rates fall 0.75%–1.0% below your existing rate, refinancing may save you significantly. On a $300,000 balance, dropping from 7.5% to 6.5% saves roughly $210/month. Factor in typical closing costs of $4,000–$6,000, and you break even in 19–29 months. After break-even, every month is pure savings. The key is ensuring you plan to stay in the home past the break-even point.

15-year vs 30-year total interest: The total interest comparison is staggering. A $320,000 loan at 6.75% (30-year) costs $427,000+ in interest. The same loan at 6.14% (15-year) costs approximately $173,000 in interest — that's a $254,000 difference. If you can afford the higher monthly payment, a 15-year loan is one of the most powerful wealth-building tools available to homeowners.

One extra payment per year: If bi-weekly feels complicated, simply make one additional full payment per year — perhaps from a tax refund, bonus, or holiday budget. On a $320,000 loan at 6.75%, this one extra payment annually saves over $55,000 in interest and eliminates approximately 5 years of payments. Specify that the extra payment applies to principal only when you submit it.

Learn more about extra payment strategies →  |  Bi-weekly payment guide →

Understanding Mortgage Rates in 2026

Your mortgage interest rate is the single biggest factor determining the total cost of your home loan — even a 0.25% difference on a $350,000 loan changes your total interest by $17,000+ over 30 years. Understanding what determines your rate and how to optimize it can save you a substantial sum.

What determines your mortgage rate: Lenders price your rate based on several factors. Your credit score is the most influential — borrowers with scores above 760 typically receive rates 0.5%–1.0% lower than those with scores in the 620–660 range. Loan-to-value ratio (LTV) matters significantly: a 20%+ down payment gets you a better rate than 5% down, because the lender takes on less risk. Loan type affects pricing too — conventional loans generally offer better rates than FHA loans for borrowers with strong credit, while jumbo loans (above $766,550 in most areas for 2026) typically carry a 0.1%–0.3% premium.

How the Federal Funds Rate affects mortgages: The Fed doesn't set mortgage rates directly, but the federal funds rate influences them through the bond market. When the Fed raises rates, the yield on 10-year Treasury bonds tends to rise, and mortgage rates follow because mortgage-backed securities compete with Treasuries for investor capital. In 2026, with the Fed holding rates steady after a series of cuts in late 2024 and early 2025, 30-year fixed rates have stabilized in the 6.5%–7.0% range — down from 2023 peaks near 8% but still elevated compared to the historic lows of 2020–2021.

Points vs. no-points: Mortgage points (also called discount points) let you buy a lower rate upfront. One point costs 1% of your loan amount and typically reduces your rate by 0.25%. On a $350,000 loan, one point costs $3,500 and might lower your rate from 6.75% to 6.50%, saving about $63/month. The break-even is roughly 56 months (4.7 years). If you plan to stay longer than that, points can make financial sense. If you might move or refinance sooner, skip the points and keep cash in hand.

Rate locks: Once you find a rate you like, a rate lock guarantees that rate for a specified period — typically 30, 45, or 60 days — while your loan closes. Longer locks may cost slightly more (0.125%–0.25%) but protect you from rate increases during underwriting. In a volatile rate environment, locking early provides peace of mind. Some lenders offer "float-down" options that let you capture a lower rate if markets improve before closing, usually for a small fee.

How to shop multiple lenders: Studies consistently show that borrowers who get quotes from at least 3–5 lenders save an average of $1,500+ over the life of their loan. Request Loan Estimates (the standardized 3-page form) from each lender on the same day to compare apples-to-apples. Focus on the APR (which includes fees), not just the advertised rate. Check local credit unions, online lenders, and mortgage brokers in addition to big banks. All credit inquiries for mortgage purposes within a 14–45 day window (depending on scoring model) count as a single hard pull, so rate-shopping won't hurt your credit score.

Refinance break-even calculator & guide →