Everyday money · General financial education

Principal vs interest share

Each payment on an amortising loan has two parts: interest on the current balance and principal that reduces that balance. Early on the interest share is often larger; later principal repayment grows.

In more detail

With a fixed payment and a positive rate, early months go mostly to interest because the balance is still high. The more principal you have already repaid, the smaller the interest share of the same payment. Extra principal payments (if the contract allows them) cut the remaining balance and thus future interest.

Background

The split is on the amortisation schedule, not only in the advertised instalment. Variable rates, fees and a balloon payment change the picture. Finmon does not model a refinance and does not recommend a product. Read the schedule: interest share and principal are two parts of the same payment.

An example

On the schedule, payment 1 shows a high interest share and little principal. By payment 48 of the same fixed instalment the principal share is larger because the balance has fallen.

A common misconception

The whole payment pays down the loan principal.

Part often goes first to interest on the remaining balance. Only principal repayment reduces the debt.

Source: BaFin · Ratenkredit. Last reviewed: 2026-11-09. Editorially reviewed on 2026-11-09. Next review 2027-11-09. Version 0.2.0. Finmon explains. It does not advise. Not investment, tax or legal advice.