Financial Calculators

Loan Calculator South Africa: Estimate Your Monthly Repayments

Work out your estimated monthly instalment, total interest and total repayment on a personal, vehicle or unsecured loan. Enter your loan amount, interest rate and term to get an instant breakdown, including any initiation and monthly service fees.

Last updated: 27 July 2026 Uses the standard reducing balance repayment formula
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Loan Repayment Calculator

Enter your loan details below, then press Calculate to see your repayment breakdown.

The total amount you want to borrow, before any fees.
Choose whichever matches how your loan agreement states the term.
The repayment period as set out in your loan agreement.
Your annual interest rate, found on your loan quote or agreement.
Optional. A once-off fee some lenders charge to set up the loan.
Optional. A monthly admin fee some lenders add to your instalment.

Your Monthly Instalment

R0

Over your loan term

Monthly Instalment
R0
Total Interest
R0
Initiation Fee
R0
Total Repayment
R0

Repayment breakdown

ComponentBasisAmount
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This estimate applies the reducing balance formula to your loan amount, interest rate and term.

Quick Answer

Your monthly loan repayment is worked out using the reducing balance method, where each instalment is a fixed amount made up of interest on the outstanding balance plus a portion of the capital, so the balance shrinks to zero by the end of the term. Total interest is the sum of all instalments minus the original loan amount. Any initiation fee and monthly service fee are added on top, since these are separate charges rather than interest. Use the calculator above for your own estimate, and confirm your exact figures with your lender’s quotation.

How to Use the Loan Calculator

Four quick steps to an estimated repayment.

  1. 1 Enter your loan amount. This is the capital amount you are borrowing, before any fees.
  2. 2 Choose whether your term is in years or months. Match this to how your loan agreement states the term.
  3. 3 Enter your loan term and interest rate. These determine your monthly instalment and total interest.
  4. 4 Add any fees and press Calculate. Your monthly instalment, total interest and total repayment appear instantly, with a full breakdown.

The Loan Repayment Calculation Formula

Loan repayments use the reducing balance method, the standard approach for personal, vehicle and home loans.

Monthly Rate = Annual Interest Rate / 12
Number of Instalments = Loan Term in Months
Monthly Instalment = Loan Amount x Monthly Rate x (1 + Monthly Rate)^n / ((1 + Monthly Rate)^n – 1)
Total Interest = (Monthly Instalment x n) – Loan Amount
Total Repayment = Loan Amount + Total Interest + Initiation Fee + (Monthly Service Fee x n)

Where the monthly rate is 0%, the monthly instalment is simply the loan amount divided by the number of instalments, with no interest charged.

Worked Examples

Real calculations using the reducing balance formula, so you can see exactly how a repayment is built.

Example 1: R50,000 loan, 0% interest, 12 months, no fees

Monthly instalment: R4,166.67Total interest: R0.00
Initiation fee: R0.00Total repayment: R50,000.00

Example 2: R20,000 loan, 24% per year, 24 months, R1,207.50 initiation fee, R69 monthly service fee

Monthly instalment (loan only): R1,057.55Monthly service fee: R69.00
Total interest: R5,381.20Initiation fee: R1,207.50
Total repayment: R28,244.70

Example 3: R150,000 loan, 13.5% per year, 6 years, no fees

Monthly instalment: R3,050.87Total interest: R69,662.64
Initiation fee: R0.00Total repayment: R219,662.64

Loan Repayments in South Africa: The Complete Guide

Whether you are looking at a personal loan, vehicle finance or another form of credit, understanding how your monthly repayment is calculated helps you compare offers and budget accurately. Almost all South African loans use the reducing balance method, where interest is charged only on the outstanding capital balance, not on the original loan amount.

How reducing balance repayments work

Each monthly instalment is a fixed amount for the life of the loan. In the early months, most of the instalment goes toward interest, since the outstanding balance is at its highest. As the balance reduces, a larger portion of each instalment goes toward capital, so the balance shrinks progressively faster toward the end of the term.

Fees regulated under the National Credit Act

Registered credit providers in South Africa are subject to the National Credit Act, which caps certain fees they may charge. The initiation fee, a once-off fee for setting up the loan, is capped at R165 for the first R1,000 borrowed plus 10% of the amount over R1,000, up to a maximum of R1,050 excluding VAT, or R1,207.50 including 15% VAT. A monthly service fee for administering the loan is capped at R60 excluding VAT, or R69 including VAT. You should always be given the option to pay the initiation fee upfront so that no interest is charged on it, rather than having it added to the loan amount.

Interest rate caps

The National Credit Act also caps the maximum interest rate credit providers may charge, using a formula linked to the South African Reserve Bank’s repo rate, with the exact margin depending on the type of credit agreement, such as a mortgage, credit facility or unsecured loan. Since the repo rate changes periodically, the applicable cap can change with it, so check the current maximum with the National Credit Regulator or your lender if you want to confirm your rate is within the legal limit.

Comparing loan offers

When comparing loans, look beyond the monthly instalment alone. Two loans with the same instalment can have very different total costs once fees and the loan term are taken into account, so compare the total repayment amount, not just what you would pay each month.

Methodology

This calculator converts your loan term to months, applies the reducing balance formula to work out your monthly instalment and total interest, then adds any initiation fee and monthly service fee you enter to arrive at a total repayment figure.

Assumptions used in this calculator

  • This calculator assumes a fixed interest rate and a fixed monthly instalment for the full term.
  • Initiation fees and service fees are entered as you expect to be charged, they are not automatically capped to the NCA maximum.
  • The initiation fee is treated as a once-off charge and is not capitalised into the loan balance.
  • This calculator does not account for credit life insurance, early settlement, or variable interest rate changes during the term.

Frequently Asked Questions

It estimates your monthly instalment, total interest and total repayment on a loan, based on the loan amount, interest rate, term and any fees you enter.

Using the reducing balance method, which spreads a fixed instalment over your loan term, charging interest only on the outstanding balance each month.

A once-off fee some credit providers charge for setting up a loan. Under the National Credit Act, it is capped at R1,050 excluding VAT, or R1,207.50 including VAT.

An ongoing monthly fee some lenders charge to administer your loan account, capped at R60 excluding VAT, or R69 including VAT.

No. This tool gives a planning estimate. Your lender’s actual quote may include credit life insurance, different fee structures, or rounding conventions that change the final figures slightly, so always confirm with your lender.

Disclaimer: This calculator provides an estimated monthly instalment, total interest and total repayment for planning purposes only, using the standard reducing balance formula. It does not account for credit life insurance, early settlement charges, variable interest rate changes, or a specific lender’s exact fee structure, and your actual repayment may differ. This tool is not affiliated with the National Credit Regulator or any specific lender, and is not financial advice. Always confirm your exact figures with your lender’s official quotation.
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