Work out percentages, percentage change, increases and discounts.
What is X% of Y?
Answer
30
20 ÷ 100 × 150
X is what percent of Y?
Answer
25%
30 ÷ 120 × 100
Percentage change from X to Y
Answer
+25%
(100 − 80) ÷ |80| × 100
Increase or decrease X by Y%
Answer
287.5 / 212.5
Increase: X × (1 + Y ÷ 100) · Decrease: X × (1 − Y ÷ 100)
Last reviewed by the OnlineToolPro team
Four everyday percentage questions in one place: X% of a number, what percent one number is of another, the percentage change between two numbers, and increasing or decreasing by a percentage.
How it works
3 simple steps. No experience needed.
Good to know
X% of Y: multiply Y by X and divide by 100 (15% of 80 = 12). X is what percent of Y: divide X by Y and multiply by 100 (12 of 80 = 15%). Percentage change: (new − old) ÷ old × 100. Increase or decrease: multiply by (1 ± X ÷ 100).
A 20% increase followed by a 20% decrease doesn't bring you back to the start: 100 → 120 → 96. Each percentage is taken from a different starting number.
FAQ
(new − old) ÷ old × 100. A change from 80 to 100 is +25%.
Use “Increase or decrease X by Y%”: 60 decreased by 25% gives 45 — the price after a 25% discount.
Going from 10% to 12% is a rise of 2 percentage points, but a 20% increase in the rate itself.
Step-by-step help for getting more out of the percentage calculator.
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