What is an equal principal payment?

It means the same amount of principal is repaid each month. Interest is added on the remaining balance, so the total payment usually decreases over time.

Is this the same as a standard amortized loan?

No. Standard fixed-payment amortization keeps the monthly payment mostly level. Equal principal keeps principal level and lets the total payment decline.

Why is the first payment higher?

The first payment includes one full fixed principal share plus interest on the largest balance.

Equal Principal Payment Calculator

Calculate a fixed-principal loan schedule with decreasing payments, principal paid each month, interest, balance, and total interest.

Loan amount ($)

APR (%/year)

Number of payments

Fixed principal and decreasing payments

This page adapts the original decreasing-payment idea to the English term equal principal payment. The principal portion stays the same each month, while interest falls as the balance declines.

First and last payment.
Equal principal paid every month.
Interest charged on the remaining balance.
Total payments, total interest, average payment, and schedule export.

Estimate only

Equal principal schedules are less common in U.S. consumer-loan search results than fixed monthly payment schedules. Confirm whether a lender actually offers this payment structure.

Equal principal formulas

P r in c i p a l = \frac{P}{n}

P is loan amount and n is the number of payments.

I n t er es t_{m} = B a l an c e_{m - 1} \cdot i

i is monthly APR.

P a y m e n t_{m} = P r in c i p a l + I n t er es t_{m}

The payment decreases as the interest portion falls.

When this schedule is useful

Use case	Why it helps
Compare structures	See how fixed principal differs from a fixed monthly payment loan.
Budget stress test	Check whether the larger first payments fit cash flow.
Interest comparison	Estimate total interest when principal is paid down faster.

Frequently Asked Questions

Sources and References

Calculations are based on the listed reference sources. Links open in a new tab.

Updated: June 2, 2026

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