Loan & Mortgage Calculator

How the payment is calculated

Start from a loan amount, or from a home price and a down payment written either as an amount or as a percent — the tool works out the loan and shows the loan-to-value as you type. Add the annual interest rate and a term in years and months, with quick chips for 5, 10, 15, 20, 25 and 30 years. The payment comes from the standard amortizing-loan formula M = P·r·(1+r)ⁿ ÷ ((1+r)ⁿ − 1), where P is the amount financed, r is the rate for one payment period and n is the number of payments — which is annual ÷ 12 and years × 12 only when you leave it on monthly. A 0% loan is simply the amount divided evenly across the payments. A term longer than 100 years is refused rather than silently truncated.

Eight payment frequencies, nine compounding conventions

Pay weekly, accelerated weekly, every 2 weeks, accelerated every 2 weeks, twice a month, monthly, quarterly or yearly. The two accelerated cycles pay a monthly payment split in half (or in quarters) on a two-week or weekly cycle, so a year holds 13 monthly payments' worth of money instead of 12 and the loan clears early on its own — the tool credits it with the interest and the months that saves, measured against the same loan on the ordinary schedule. Nine compounding conventions decide what the quoted rate actually means: annually (so the number is an APY), semi-annually (the Canadian mortgage convention), quarterly, monthly (US and UK), twice a month, every 2 weeks, weekly, daily and continuously. A 6% note compounded semi-annually and paid monthly works out at (1.03)^(1/6) − 1 a month, slightly less than 0.5%. When the payment is not monthly the result also restates it per month, so two frequencies can be compared side by side.

Taxes, insurance, PMI and HOA

Open Taxes, insurance, PMI & HOA for a full PITI figure. Property tax goes in as an amount per year or as a percent of the home price; home insurance is per year, HOA and PMI per month. Tax, insurance and HOA each take their own annual increase rate, applied year after year, so a 2% yearly tax rise sits in the totals instead of being assumed away. PMI stops on its own once the balance falls to 80% of the home price: the page names the payment it stops at, the date it stops, and the total PMI paid by then. Without a home price there is nothing to measure the balance against, so PMI runs for the whole term and the page says exactly that rather than quietly guessing a value you never typed.

Extra payments

Extra principal goes in three ways at once: a fixed amount on every payment from a month you choose, one extra payment a year in the month you choose, and up to ten one-time lump sums, each on its own month. A lump sum dated outside the term is refused with a message that names the problem rather than being moved to month 1, and a negative amount anywhere is refused rather than read as zero.

Fees, APR and effective APR

Open Fees & APR for an origination fee as a percent of the loan, other fees paid at closing, and fees rolled into the balance. Closing fees come out of the cash you actually receive; financed fees are added to what the schedule amortizes. The moment any fee is entered the page shows the amount financed, the APR — the periodic rate that prices the contractual payments against that net cash, found by bisection because no closed form exists once the last payment is a different size from the rest, then annualized — and the effective APR, the same rate compounded over a year. With no fees, and compounding that matches the payment frequency, the APR is simply the rate on the note.

The schedule, the charts, and taking it with you

The schedule has two views: one row a year, or one row for every payment — 360 rows for a 30-year monthly mortgage, 780 for the same loan paid every 2 weeks. The start date opens on today, so every row carries its due date and the summary carries a payoff date. Two charts are drawn from the same schedule as the table, so the picture and the numbers cannot disagree: a pie of principal (fees added to the loan included) against interest against tax, insurance, PMI and HOA, and the balance falling year by year. Whichever view is on screen downloads as CSV, and the Print button drops the site header, footer and ads and expands the table so no row is cut off at a scroll edge. Every field — extra payments and fees included — lives in the query string, so a copied link reopens the exact quote, and Clear puts every field back to its default.

Why early payments are mostly interest

With a fixed-rate loan each payment is the same, but its split changes over time. Early on, most of the balance is outstanding, so most of each payment goes to interest and only a little to principal. As the balance shrinks, the interest portion drops and more goes to principal, which is why the balance falls slowly at first and faster near the end. Everything here is a fixed-rate estimate, computed in your browser — nothing you type is uploaded — and tax, insurance, PMI, HOA and fees are included only when you enter them.