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How to Calculate Your Mortgage Payment (2026 Guide)
Published: June 2026 | Reading time: 5 minutes
Whether you're buying your first home or refinancing an existing loan, understanding how your monthly mortgage payment is calculated puts you in control. Here's exactly how the math works — no finance degree required.
The Mortgage Payment Formula
For a standard fixed-rate mortgage (equal monthly payments), the formula is:
M = P × [ r(1+r)n ] / [ (1+r)n − 1 ]
Where:
- M = Monthly payment
- P = Loan principal (amount borrowed)
- r = Monthly interest rate (annual rate ÷ 12)
- n = Total number of payments (years × 12)
Example: $300,000 Loan at 6.11% for 30 Years
Let's walk through a real calculation:
- P = $300,000
- r = 6.11% ÷ 12 = 0.0050917
- n = 30 × 12 = 360
- (1 + r)n = (1.0050917)360 ≈ 6.225
- M = 300,000 × (0.0050917 × 6.225) / (6.225 − 1)
- M = 300,000 × 0.031704 / 5.225
- M ≈ $1,820.06
Try it instantly: Don't want to do the math by hand? Our free calculator does all of this automatically, plus shows your full amortization schedule.
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What Makes Up Your True Monthly Payment?
Your actual housing payment is more than just principal and interest. Most lenders escrow (collect) additional costs monthly:
- Principal: The loan amount you're paying back
- Interest: The cost of borrowing
- Property Tax: Annual tax ÷ 12 (varies by county, typically 0.5%–2.5% of home value)
- Homeowners Insurance: Annual premium ÷ 12 (~$100/month average)
- PMI: Private Mortgage Insurance if your down payment is less than 20%
- HOA: Monthly fee if your property is in a homeowners association
Use our
Full Cost Calculator to see your complete PITI (Principal, Interest, Tax, Insurance) breakdown.
Equal Payment vs Equal Principal: What's the Difference?
| Equal Payment (Amortized) | Equal Principal |
|---|
| Same payment every month. Early payments are mostly interest. Most common in the US. | Same principal payment each month. Total payment decreases over time. Less total interest paid. |
Frequently Asked Questions
Does my interest rate change over time?
Not with a fixed-rate mortgage. Your rate is locked for the entire loan term. With an adjustable-rate mortgage (ARM), the rate can change after an initial fixed period (typically 5, 7, or 10 years).
How much can I save by making extra payments?
Even $100 extra per month can save you tens of thousands in interest and cut years off your loan. Try the Extra Payment feature in our mortgage calculator to see exactly how much.
What credit score gets the best mortgage rate?
A credit score of 740+ typically qualifies for the lowest advertised rates. If your score is below 620, you may want to consider an FHA loan. Use our AI loan approval tool to check your estimated approval odds.
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