Mortgage payment calculator

What actually makes up your payment

Your monthly mortgage payment is rarely just principal and interest. Lenders typically collect property tax and homeowners insurance alongside it, holding the money in an escrow account and paying those bills on your behalf when they're due. If your down payment is under 20%, PMI usually gets added on top of that, protecting the lender (not you) against default risk.

The "total monthly payment" figure above is the realistic number to budget against — not just the principal-and-interest figure most rate quotes advertise, which is usually the smaller, more attractive-looking number.

Read the full guide: PMI Explained: When It Drops Off and How to Avoid It →

Four components, two behaviors

A mortgage payment is usually quoted as one number, but it's assembled from parts that behave differently. Principal and interest are fixed on a fixed-rate loan — genuinely fixed, for thirty years. Taxes and insurance are not fixed at all; they're pass-through amounts your servicer collects and forwards on your behalf.

This split explains the most common confusion in homeownership: how a fixed-rate payment goes up. The rate didn't change and the loan didn't change. Your property tax assessment and your insurance premium did, and the escrow portion adjusts to match. Add HOA dues and mortgage insurance where applicable, and the "fixed" payment has more moving parts than the name implies.

Early payments are mostly interest, and it's not close

Amortization allocates each payment between interest and principal based on the current balance. Because the balance is highest at the start, the interest share is largest at the start — and the crossover point where principal exceeds interest arrives much later than most people expect on a 30-year loan.

The amortization schedule this calculator produces makes the shape visible. It's worth scrolling to the bottom once, because the total interest figure over thirty years is the number that changes how people think about term length and extra payments. It routinely approaches or exceeds the amount borrowed.

Two things follow. A 15-year term costs dramatically less in total interest, not merely proportionally less, because you spend far less time in the interest-heavy early portion. And extra principal applied early has outsized effect for the same reason — each dollar removed from the balance in year two avoids interest for twenty-eight years.

What a lower rate is actually worth

Rate shopping gets framed around monthly payment differences, which understates the stakes. A quarter-point difference on a $400,000 loan is a modest monthly amount — small enough that borrowers accept a worse rate for convenience. Across the full term, that same quarter point is a five-figure sum.

Run two scenarios in the calculator and compare total interest rather than monthly payment. The monthly view makes rate differences look trivial; the lifetime view makes clear why a few hours of shopping is among the highest-value work in the entire transaction.

The same reframing applies to loan amount. Borrowing $20,000 more doesn't cost $20,000 — it costs $20,000 plus thirty years of interest on it, which is why the gap between what you're approved for and what you should borrow deserves genuine thought.

What this calculator can't see

Estimates are only as good as their inputs, and several of these inputs are guesses until a real transaction is underway.

Use this to compare scenarios against each other, which it does well, rather than to predict a closing statement to the dollar. For that you need a Loan Estimate from a lender — which they're required to provide within three business days of application, and which is the only figure that carries any weight.