About this site
Who makes this, why it exists, and how it pays for itself.
Why it exists
Ask what a loan costs and most people answer with the monthly payment. But two loans with identical payments can differ by tens of thousands of dollars, because the payment says nothing about how long you pay it or how much of it is interest.
Almost every calculator online stops at that single number. InterestLoanCalculator.com exists to show the rest: the full schedule, the split between interest and principal on every payment, the crossover point, and what changes when you pay a little more.
How it is built
- Everything runs in your browser. No figure you type is transmitted, stored or shared. There is no account and no form.
- The formulas are published. Our methodology page sets out every equation and every assumption, so you can check any result by hand.
- The maths is tested. A $350,000 loan at 6.5% over 30 years returns a payment of $2,212.24 and total interest of $446,405.71, and every schedule repays the principal exactly to the cent.
- No lead generation. We do not sell your details to lenders. There is nobody waiting on the other side of the results, because there is no other side.
How it makes money
Two ways, both disclosed. Display advertising served by Google, and Amazon affiliate links on a short list of genuinely relevant products. Neither changes what the calculators say, and neither costs you anything. The full affiliate disclosure explains both.
We deliberately do not take lender referral fees. The moment a calculator's owner is paid per application, the incentive to present the numbers honestly disappears.
Contact
Corrections, questions and bug reports are all welcome, and corrections especially — if a number here is wrong we want to know.