Percentage Calculator
Work out percentage changes, salary increases, discounts and mark-ups on South African amounts — with the formula shown for every result.
By Hiree Editorial · Independent educational publisher · Published 18 August 2026 · Updated 3 September 2026
Percentage increase
+20.00%
Change in rand
R 3 000,00
From
R 15 000,00
To
R 18 000,00
Percentage change = (new amount − old amount) ÷ old amount × 100. Use this to work out salary increases, price rises, or how much an expense has grown.
How each calculation works
A percentage is just a fraction out of 100. Most money questions in South Africa — a salary increase, a discount, VAT on a price — reduce to one of a few simple formulas:
Percentage of an amount
Multiply the amount by the percentage and divide by 100. For example, 15% of R4,000 is R4,000 × 15 ÷ 100 = R600. This is the building block behind every other mode.
Percentage change
Subtract the old amount from the new amount, divide by the old amount, then multiply by 100. A salary that rises from R15,000 to R18,000 has increased by (R18,000 − R15,000) ÷ R15,000 × 100 = 20%. This is the most useful mode for real life — it tells you whether a raise, a price rise or a quote difference is big or small.
Add, subtract and discounts
To add a percentage, multiply the amount by (1 + percentage ÷ 100). A 10% increase on R2,000 is R2,000 × 1.10 = R2,200. To subtract, multiply by (1 − percentage ÷ 100): a 25% discount on R2,000 leaves R2,000 × 0.75 = R1,500, saving R500.
Worked examples for South African money
Salary increase
You earn R20,000 a month and get a 7.5% increase. Your new salary is R20,000 × 1.075 = R21,500. The raise is worth R1,500 a month, or R18,000 a year before tax. Run this with the "add" mode, or use the "change" mode to compare two actual salaries.
Store discount
A R899 appliance is marked "30% off". The saving is R899 × 30 ÷ 100 = R269.70, so you payR629.30. Check the till slip: many "was/now" prices round, and a 30% discount should always mean you pay 70% of the original.
Percentage change in a price
Your medical aid premium goes from R3,200 to R3,520. That's (R3,520 − R3,200) ÷ R3,200 × 100 = 10%. Comparing increases this way is fairer than comparing the rand amounts alone, because it accounts for the starting point.
Important limitations
- This is arithmetic, not a financial statement. It does not apply tax, inflation, compound growth or fees. For those, use the dedicatedPAYE or loan calculators.
- A percentage change is not symmetric. If a price rises 25% and then falls 25%, it does not return to the start — a R100 item rising 25% becomes R125, and a 25% fall from R125 leaves R93.75.
- A zero starting amount breaks percentage change. Going from R0 to another amount has no defined percentage change, so the tool reports it as undefined — use absolute rand instead.
- Rounding is to the nearest cent. Official statements and payroll may round differently on large or split amounts.
Frequently asked questions
How do I work out a percentage increase on a salary?
Divide the increase by the old salary and multiply by 100. A salary moving from R12,000 to R13,500 increased by (R1,500 ÷ R12,000) × 100 = 12.5%. Use the "percentage change" mode with the old salary as the first amount and the new salary as the second.
What is the difference between a percentage and a percentage point?
A percentage is one part in a hundred; a percentage point is the arithmetic difference between two percentages. If VAT rises from 14% to 15%, that is a rise of 1 percentage point — but a relative increase of about 7.14%. Confusing the two is how a "1% increase" gets quoted as "1 percentage point" and vice versa.
How do I add VAT using a percentage?
To add 15% VAT, multiply by 1.15 — that's the "add" mode with 15%. To find the VAT inside a VAT-inclusive price you need the 15/115 rule rather than a plain 15% subtraction, which is exactly what the VAT calculator handles for you.
Why doesn't a 25% rise and a 25% fall cancel out?
Because the second percentage is calculated on a different base. R100 up 25% is R125; down 25% from R125 is R93.75, not R100. Percentage changes always act on the amount they start from, which is why order matters.
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