Equal-Principal Amortization Calculator
In an equal-principal (constant amortization) loan, you repay the same principal amount each month, so payments start high and shrink over time. See the first payment, last payment, and total interest — and how much interest you save versus a standard equal-payment loan.
Inputs explained
- Loan amount — The principal borrowed.
- Annual interest rate — The loan's yearly interest rate.
- Loan term — The repayment period in months.
How to use it
- Fill in the fields above — each input has a hint describing exactly what to enter
- Press Calculate to get your result instantly, right on this page
- Copy the result, save the tool to favorites, or share and embed it anywhere
Understanding the result
Example: A $100,000 loan at 6% over 240 months has a $916.67 first payment, a shrinking balance, and $60,250 total interest.
Frequently asked questions
How is this different from a standard (equal-payment) amortization schedule? A standard loan keeps the monthly payment constant while the principal-to-interest mix shifts over time. This calculator instead keeps the principal portion constant each month, so the total payment starts higher and decreases as the balance shrinks.
Why is the first payment so much higher than later payments? The first payment carries a full month of interest on the entire original balance plus the fixed principal amount, so it's the largest payment you'll make; every subsequent payment is smaller because interest is charged on a shrinking balance.
Is the Equal-Principal Amortization Calculator free to use? Yes — it is completely free, with no sign-up, no download and no usage limits. You can use it as often as you need.
Is my data private? Yes. The calculation runs entirely in your browser — the values you enter are never sent to our servers, stored or shared with anyone.
What information do I need? Just the following: Loan amount, Annual interest rate, Loan term. Each field includes a hint explaining exactly what to enter.
Can I use it on my phone? Yes — the tool is fully responsive and works on any device, and the same calculator is available in the EasyWorkCalcs mobile app.
Privacy
Everything you enter into the Equal-Principal Amortization Calculator is processed entirely in your browser. Nothing is uploaded, stored or shared — your data stays on your device.