Choose your escalation method

Fixed %: you enter the percentage written in the lease (this tool caps it between 0% and 20% for illustration). CPI-linked: the increase follows the CPI figure you enter (often the latest Stats SA annual rate). Hybrid (CPI + cap): CPI is used when positive, you add a margin (for example 2% above CPI), and the total cannot exceed your maximum escalation clause. Pick the option that matches your lease wording.

Calculate the increase percentage

For a fixed lease clause, the increase % is exactly what you typed. For CPI-linked, the tool uses your CPI input (allowed between -5% and 25% to catch data entry errors). For hybrid, if CPI is zero or negative, the CPI portion is treated as 0%; if CPI is positive, your margin is added. The total is then limited by your maximum % cap so the escalation cannot exceed what the lease allows.

Apply the increase to monthly rent (ZAR)

Increase amount = current monthly rent × (increase % ÷ 100). New rent = current rent + increase amount. Annual impact shows how much extra rent you would collect over twelve months if the new amount applied for a full year. All amounts are in South African Rand (ZAR), excluding utilities or levies unless your lease says otherwise.

Work through the formula

The formula block turns the increase percentage into rands. Current rent is what the tenant pays today. The increase % comes from step 2. Multiplying by 12 projects one year's difference; it does not replace a written escalation notice or CPA fairness test.

Read the 3-year illustration

The projected 3-year total assumes the same percentage increase is applied every year, each time on the rent that grew the previous year. Real CPI and market rents change annually, so treat this line as a scenario only. It helps compare methods side by side, not to fix rent three years ahead without review.

Core formulas

New rent = Current rent × (1 + increase%÷100) Annual impact = (New rent − Current rent) × 12

Current rent: monthly rental in ZAR before the escalation. increase%: the lawful escalation rate from your fixed, CPI, or hybrid calculation. New rent: what the tenant would pay per month after one increase. Annual impact: extra rent over 12 months at the new monthly amount (not compounded across future years). The 3-year figure in the calculator compounds the same % on the growing rent for years two and three.

You still need reasonable notice (often 40 to 60 days for residential leases), comparable rentals if you exceed CPI materially, and a lease clause that supports the method. This tool is a calculation aid, not legal advice. Disputes go to the Rental Housing Tribunal or an attorney.

What does the CPA say about rent increases?

The Consumer Protection Act prohibits unfair, unreasonable, or unjust contract terms. While it does not cap rent increases directly, the Rental Housing Tribunal has consistently ruled that increases must be reasonable and market-related. CPI-linking is the safest harbour.

Can I increase by more than 10%?

Technically yes, but you risk a Tribunal challenge. If you do, you must prove comparable rentals in the area have risen similarly, you have made substantial capital improvements, or the tenant's rental was materially below market. Document everything.

How much notice must I give?

The Rental Housing Act requires reasonable notice. Tribunal precedent treats 1–2 months as reasonable for residential leases. Our default is 60 days. If your lease specifies a longer period, that clause governs.

Is this legal advice?

No. This tool estimates increases from your inputs. Consult an attorney or the Rental Housing Tribunal for disputes or complex lease terms.