Equal Payment Amortization Calculator
Calculate the monthly payment, total interest, and schedule for equal payment amortization.
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Enter the loan principal, term, and interest rate.
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Equal payment amortization is the most commonly used repayment method in financial loans such as mortgages and personal loans. As the name suggests, the key is repaying the same amount (principal + interest) every month throughout the loan term.
Because the monthly payment is constant, it is very easy to plan long-term finances, and it is especially preferred by salaried workers with stable income. This calculator accurately computes your monthly payment based on your loan terms and shows the entire schedule at a glance, helping you build a stable financial plan.
Term Glossary
- Equal payment repayment
- A method of repaying the same amount (principal + interest) every month throughout the loan term; the easiest to plan finances around.
- Grace period
- A period during which you pay only interest and defer principal repayment; eases the immediate burden but increases total interest.
- Early repayment fee
- A fee charged when a lump sum lets you repay principal early after taking the loan, usually applied for up to 3 years.
The equal payment installment amount is calculated through a complex formula. You pay the same amount each month, but the principal and interest shares within it change every time.
1. Monthly payment (fixed) formula
※ Monthly rate = Annual rate / 12
2. Monthly principal and interest
The monthly payment is fixed, but its composition changes each month.
- Monthly interest (decreasing):
- Monthly principal (increasing):
Early on the interest share is high, and over time the principal repayment share grows.
🏠 Buying a home: 2025 loan strategy guide
1. Equal payment vs equal principal: which fits you?
The biggest difference between the two is the initial repayment burden and the total interest cost.
Equal payment (this calculator)
- Pros: Same monthly payment (easy planning)
- Cons: More total interest than equal principal
- Recommended for: Salaried workers and new grads with stable, predictable income
Equal principal
- Pros: Least total interest cost
- Cons: High initial burden (payment decreases over time)
- Recommended for: Those with ample initial funds who want to minimize interest, or retirees expecting lower income
2. Tighter 2025 DSR rules and stress DSR
From 2025, loan screening becomes stricter. The stress DSR system is key.
- DSR (Debt Service Ratio): The ratio of total annual principal and interest of all loans to annual income. Banks currently apply 40%.
- Stress DSR: A method that adds a stress rate to the actual loan rate to calculate DSR, preparing for future rate hikes.
- Result: Even with the same income and loan, the added rate reduces the limit versus the past. You must expect a lower limit than anticipated.
3. Early repayment fee: remember the "3-year rule".
The early repayment fee arises when you want to repay principal early after taking a loan. It is usually charged for up to 3 years after origination.
- The fee is typically 1.2%–1.5% and gradually decreases over time (sliding scale).
- Strategy: If you plan to repay within 3 years, look for fee-waived products or compare the fee with the interest saved. After 3 years you can repay principal freely without a fee.
4. Do you really need a grace period?
A grace period is a time when you pay only interest and defer principal. It eases the immediate burden but greatly increases total interest.
- The later principal is repaid, the more total interest is paid over the whole term.
- Strategy: Unless unavoidable (e.g. early move-in costs), it is better long-term not to set or to minimize the grace period.