Use this calculator to estimate monthly mortgage repayment from loan amount, interest rate, and loan term. It helps property investors understand debt cost before assessing yield, cash flow, or affordability.

What this calculator does

The mortgage repayment calculator estimates the monthly payment required to repay a loan over a fixed term.

It uses:

loan amount
annual interest rate
loan term in years
monthly repayment

This gives the expected monthly mortgage payment for planning property cash flow.

How to use the mortgage repayment calculator

Enter the loan amount, annual interest rate, and loan term. The rate should be entered as an annual percentage, not a monthly rate.

For a zero interest loan, the repayment is the loan amount divided by the number of months.

Mortgage Repayment Formula

Monthly repayment = P x r(1 + r)^n / ((1 + r)^n - 1)

Where P is the loan amount, r is the monthly interest rate, and n is the total number of monthly payments.

Example calculation

If:

Loan amount = 300,000
Annual interest rate = 6%
Loan term = 30 years
Monthly repayment = 1,798.65

A 300,000 mortgage at 6% over 30 years has an estimated monthly repayment of 1,798.65.

What is a mortgage repayment?

A mortgage repayment is the scheduled amount paid to a lender each month. In a standard amortizing mortgage, each payment includes interest and principal.

Early payments are usually more interest-heavy. Later payments reduce more principal as the outstanding balance falls.

Interpreting your result

The monthly repayment is central to cash flow. A property with attractive rent can still be weak if the mortgage payment absorbs most of the income.

Use the Amortization Calculator to review principal and interest over time, and the Loan Payment Calculator for general borrowing comparisons.

When to use this calculator

Use this calculator when you want to:

estimate monthly debt cost
compare loan terms
test interest rate changes
assess rental cash flow

Common mistakes

Common mistakes include:

entering monthly interest as annual interest
ignoring fees and insurance
assuming rates never change
comparing loans with different terms

FAQs

Does this calculate interest-only mortgages?

No. This formula estimates a standard amortizing repayment.

What happens at zero interest?

The repayment is simply the loan amount divided by the total number of months.

Mortgage Repayment Calculator