Separate the amount you receive from the balance that earns interest

A personal loan can deliver R20,000 of usable cash while beginning with a balance above R20,000 because a lender adds an establishment fee. The amount-borrowed field is the cash required for the purchase, expense or consolidation. When “Add fee to the loan balance” is selected, the fee increases the principal used by the repayment formula. When it is paid upfront, the fee remains a cash cost but does not accrue interest.

Repayment formula for a fixed rate

The calculator uses an amortising annuity. The periodic rate equals the annual percentage divided by the number of repayments per year and by 100. The payment count is the selected term in months converted to the chosen cycle. Repayment equals financed principal multiplied by r(1+r)ⁿ, divided by (1+r)ⁿ minus 1. At 0%, principal is divided evenly by the number of payments. The ongoing account fee is then added to the cash payment.

The model assumes the rate and fee do not change and every payment arrives on time. It does not add default interest, missed-payment fees or collection charges. A variable-rate personal loan needs at least one higher-rate scenario because the initial repayment is not a ceiling. A fixed-rate loan may keep the scheduled payment stable but can restrict early repayment or charge an early termination amount.

A longer term buys monthly room by keeping debt alive

Term is often the most powerful lever after the rate. Extending a loan spreads principal over more payments, so each payment falls. The balance also remains outstanding longer, which normally increases interest, and a per-payment fee is charged more times. The comparison table holds the amount, rate and fee structure constant so the term trade-off is not confused with a different loan offer.

Worked example: R20,000 over four years

Assume a R20,000 personal loan, a R250 establishment fee financed into the balance, a 10.5% annual rate, a 48-month term and a R5 monthly fee. The interest-bearing balance is R20,250. The scheduled loan instalment is approximately R518.47, so monthly cash payment is about R523.47. Interest is about R4,636.49 and nominal fees total R490: the R250 establishment fee plus 48 lots of R5. Total repayment is about R25,126.49, making borrowing cost approximately R5,126.49 above the R20,000 received.

At 36 months, the monthly cash figure rises to about R663.17 but borrowing cost falls to roughly R3,874.28. At 60 months, cash payment falls to about R440.25 while borrowing cost rises to around R6,415.09. The longer option frees approximately R223 each month compared with the short option, yet costs about R2,541 more overall. A useful choice is the shortest term that remains resilient after essential expenses and a realistic emergency buffer.

Use the comparison rate as a screen, then model the actual contract

South African consumer loan advertising commonly shows a comparison rate that includes interest and most fees using a prescribed example. It helps expose an offer with a low headline rate and expensive standard fees. It does not guarantee the same effective cost for your amount, term, repayment pattern or optional products. Enter the interest rate that actually accrues on the balance and the fees stated for the proposed contract.

• Rate basis: Is the rate fixed for the term or able to change, and is a discount conditional on automatic payment or another product?
• Fee timing: Is the establishment fee deducted from the advance, paid separately or capitalised into the balance?
• Payment cycle: Does the quoted account fee apply monthly even when repayments are fortnightly, or is it charged on every repayment?
• Exit terms: Can extra repayments be made, is redraw available, and does early payout create a fee?

This calculator treats the ongoing fee as applying on every selected repayment because that is what the field says. If a lender charges R10 per month while accepting fortnightly repayments, convert the monthly fee to the correct contract cash flow rather than entering R10 per fortnight. Fee timing has little effect on the advertised rate but can change the sum paid and the account balance used by a detailed schedule.

Secured and unsecured loans carry different risks

A secured loan gives the lender rights over an asset if repayments are not made and may offer a lower rate. An unsecured loan does not name that security but can cost more and still creates an enforceable debt. A lower calculation is not enough to choose between them. Check what asset is at risk, whether a guarantor is involved and what happens after a missed payment.

Rebuild the scenario when cash flow or contract terms change

The result assumes equal instalments and no balloon. It is not suitable for a line of credit, buy-now-pay-later plan, payday loan, interest-only period, construction drawdown or contract with a residual payment. It also does not calculate a lender’s comparison rate or annual percentage rate from fees. Those products have cash-flow patterns that cannot be represented accurately by one amount, one fixed rate and one end date.

For debt consolidation, calculate the new loan and then compare it with the remaining payments, rates and fees on each existing debt. A lower single payment can come from a much longer term and may increase total cost. Close or reduce unused revolving credit only as appropriate to the plan; otherwise the new instalment can be added to fresh card debt rather than replacing it.

If an extra payment is expected, request the lender’s allocation rules. Some contracts reduce principal immediately, while others treat money as payment in advance or retain a fixed direct-debit amount. A settlement quote on a specific date can include accrued interest and charges not visible in a simple amortisation result. Keep the calculator comparison with the written offer, not as a substitute for it.

Affordability should survive a small shock. Put the selected repayment into a budget, raise any variable rate by two or three percentage points, and test a month with higher essentials. Include annual bills by converting them to a regular allowance rather than pretending they arrive from spare money. If the loan only works when every discretionary dollar is used, choosing a smaller principal can be safer than stretching the term until the displayed repayment fits.