Loading calculator…
Loading calculator…
Example outcomes
Interest accrued for common deposit amounts and rates over a 1-year period (monthly compounding).
| Deposit | 5% p.a. | 6.5% p.a. | 8% p.a. |
|---|---|---|---|
| R 5 000,00 | R 255,81 interest | R 334,86 interest | R 415,00 interest |
| R 8 500,00 | R 434,88 interest | R 569,26 interest | R 705,50 interest |
| R 12 000,00 | R 613,94 interest | R 803,66 interest | R 995,99 interest |
Fixed example amounts and rates. Use the calculator above for your own dates and settings.
How to calculate deposit interest step by step
In South Africa, the Rental Housing Act (RHA) requires landlords to invest a tenant's deposit in an interest-bearing account. Interest belongs to the tenant when the lease ends, minus lawful deductions such as outstanding rent or repair costs. This calculator estimates how much interest accrued between two dates. It uses monthly compounding, which is how many banks credit savings over part of a year.
Gather your deposit details
Enter the deposit amount (the cash the tenant paid on signing). Add the start date (usually when the deposit was received or the lease began) and the end date (often inspection day or key hand-back). Use the annual interest rate shown on the account statement where the deposit was held. If your lease caps the deposit at two months' rent, check that your amount matches what was actually invested.
Count how long the deposit was held
The tool counts every calendar day from start to end, both days included. That day count is divided by 365 or 366. If the whole period falls in one calendar year, a leap year uses 366 days; otherwise 365. This matches how many landlords and the Rental Housing Tribunal treat short residential periods.
Understand monthly compounding
Compounding means interest is calculated on the growing balance, not only on the original deposit. Each month, one twelfth of the annual rate is applied. Those twelve monthly steps are scaled to the fraction of a year you actually held the money (days divided by year days). The result is the balance after interest; subtract the deposit to get interest owed.
Work through the formula
See the formula block below. In plain terms, the deposit grows by applying the monthly rate repeatedly for your holding period. Interest is that final balance minus the deposit. Total refund before deductions is deposit plus interest.
Apply lawful deductions at refund
After interest, the landlord may deduct only lawful items agreed in the lease or supported by evidence: arrear rent, damage beyond fair wear and tear, reasonable cleaning, or other Tribunal-accepted charges. The balance must be paid to the tenant within a reasonable time. If you dispute the amount, you may approach the Rental Housing Tribunal in your province.
Formula used in this tool
Interest = Deposit × (1 + rate÷12)^(12 × days÷yearDays) − Deposit Total = Deposit + Interest
Deposit: the principal amount invested. rate: annual interest percentage (per year) on the account. days: calendar days held, start and end inclusive. yearDays: 365 or 366 when the period sits in one leap or normal year. (1 + rate÷12): converts the annual rate into one month's growth factor. 12 × days÷yearDays: spreads twelve monthly compounding steps across your actual holding period. Subtract Deposit at the end so the line shows interest only, not the full balance.
This is an estimate for planning and negotiations, not legal advice. Some Tribunal matters use simple interest instead of compounding. Always compare the result with your bank statement and your signed lease.
Frequently asked questions
Must my deposit earn interest?
Yes. The Rental Housing Act requires deposits to be invested in an interest-bearing account, and interest to be paid to the tenant on termination, subject to lawful deductions.
What can be deducted from my deposit?
Lawful deductions typically include unpaid rent, damage beyond fair wear and tear, and agreed cleaning costs, supported by evidence such as quotes or receipts.
How quickly must a deposit be refunded?
There is no fixed statutory day count, but landlords commonly aim for 7–14 days after handover and inspection. Unreasonable delay can be challenged at the Rental Housing Tribunal.
Is this legal advice?
No. This calculator provides an estimate based on your inputs. Consult an attorney or the Tribunal for disputes or complex situations.