About Crunch My Mortgage
A free, independent set of mortgage calculators that explain their own math.
What this site is
Crunch My Mortgage is a collection of 17 mortgage calculators, each built to answer one question well: what a payment will be, how much house an income supports, when a refinance or a set of discount points pays for itself, when private mortgage insurance can end, and more. Every calculator sits on its own page next to a plain-English explanation of the formula it uses, a worked example with real numbers, common mistakes and the limits of the estimate.
The site is independently published.
Free, with no sales pitch
Every calculator is free to use, with no account, no email sign-up and no paywall. Crunch My Mortgage does not take loan applications, quote rates, collect leads or sell visitor information, and no lender pays to be featured. The site is supported by advertising, which is always labeled and kept away from the calculators themselves.
How the calculators are built
- Your numbers, not ours. Results come from what you type. There are no market rates, no "today's rates" and no local data that could quietly go out of date. Starting values in each form are placeholders for you to replace.
- Standard formulas, shown in full. Each page states the formula it uses and walks through an example, so you can check the result by hand or against your lender's documents.
- Tested. The math is covered by automated tests anchored on known values, such as a $300,000 loan at 6% for 30 years costing $1,798.65 a month in principal and interest, plus edge cases like zero interest and extra payments larger than the balance.
- Private by design. Calculations run in your browser. Nothing you enter is sent to us. See the privacy policy.
- Official sources for official numbers. The only reference tables on the site are the official FHA mortgage insurance and VA funding fee tables. Each is shown with its government source and the date it was last checked.
What the results are, and are not
Every result is an estimate for education. It is not a loan offer, a rate quote or financial advice, and actual terms come from a lender. Read the full disclaimer.
Get in touch
Spotted an error, or have an idea for a calculator? The contact page has the address. Corrections are always welcome.