Percentage calculator
Type your numbers and the answer appears straight away, with the working shown. Covers “what is 15% of 200”, percentage change, adding or removing VAT, discounts and more.
What is % of ?
= 30
15% of 200 = 200 × 0.15 = 30
is what % of ?
= 15%
30 ÷ 200 × 100 = 15%
Percentage change from to
= 25%
(100 − 80) ÷ 80 × 100 = 25%, a 25% increase
Add % to (e.g. VAT, tip, mark-up)
= 230
200 + 15% = 200 × 1.15 = 230 (the 15% part is 30)
Take % off (e.g. a discount)
= 399.2
499 − 20% = 499 × 0.8 = 399.2 (you save 99.8)
Remove % from that already includes it (e.g. VAT)
= 200
230 ÷ 1.15 = 200 before the 15% was added (the 15% part is 30)
is % of what?
= 200
30 ÷ 0.15 = 200
Percentage formulas in plain words
- X% of Y: Y × X ÷ 100. 20% of 350 = 70.
- X is what percent of Y: X ÷ Y × 100. 45 out of 60 = 75% (handy for test marks).
- Percentage change: (new − old) ÷ old × 100. A price going from R80 to R100 is up 25%.
- Add a percentage: Y × (1 + X ÷ 100). R200 + 15% VAT = R200 × 1.15 = R230.
- Take a percentage off: Y × (1 − X ÷ 100). 20% off R499 = R399.20.
- Remove a percentage that’s already included: Y ÷ (1 + X ÷ 100). R230 including 15% VAT = R200 before VAT.
Everyday examples
Shopping: a 30% discount on R1,200 saves R360, so you pay R840. Two discounts don’t add up: 20% off and then another 10% off is 28% off in total, not 30%. Tips: a 10% tip on a R450 bill is R45; 15% is R67.50. Marks: 38 out of 50 is 76%. Salary: a raise from R25,000 to R26,500 is a 6% increase. Interest and inflation: if prices rise 5% a year, something that costs R100 today costs about R128 in five years, because each year’s rise is on top of the last.
South African VAT is 15%, so the VAT inside any VAT-inclusive price is that price × 15 ÷ 115 (about 13.04% of the total). Need dates instead? Try the days between dates calculator.
Frequently asked questions
How do I work out a percentage of a number?
Multiply the number by the percentage and divide by 100. 15% of 200 is 200 × 15 ÷ 100 = 30. A quick trick: 10% is the number with the decimal point moved one place left (10% of 250 is 25), so 5% is half of that and 20% is double it.
How do I calculate percentage increase or decrease?
Subtract the old value from the new value, divide by the old value and multiply by 100. From 80 to 100 is (100 − 80) ÷ 80 × 100 = a 25% increase. From 100 to 80 is a 20% decrease, because you divide by the starting value.
How do I add 15% VAT to a price in South Africa?
Multiply the price by 1.15. R200 excluding VAT is R230 including VAT, and the VAT part is R30. Use the “add a percentage” calculator above with 15.
How do I remove VAT from a price that already includes it?
Divide by 1.15, don’t subtract 15%. R230 including VAT ÷ 1.15 = R200 before VAT. Taking 15% off R230 gives R195.50, which is wrong, because the VAT was 15% of the smaller, pre-VAT price.
Why doesn’t a 50% rise followed by a 50% drop get me back to where I started?
Because each percentage is taken from a different starting point. 100 up 50% is 150, and 150 down 50% is 75. The drop is 50% of a bigger number, so you end lower than you began.
What is the difference between percent and percentage points?
Percentage points are a plain subtraction of two percentages. If an interest rate goes from 10% to 12%, it rose by 2 percentage points, which is a 20% increase in the rate itself.