Tool

Percentage Calculator

Three modes: find a percentage of a number, work out what percentage one value is of another, or calculate percentage change. Pick a mode, type your numbers.

What is% of?

Calculate percentages in three steps

Three modes. Every common percentage question covered.

1

Choose your calculation

Pick from 'What is X% of Y?', 'X is what % of Y?', or 'Percentage change from X to Y'.

2

Enter your numbers

Fill in the values. The result appears as you type.

3

Get your answer

See the calculated value with the formula used.

Percentage Calculator

X% of Y
X of Y
% change
Percentage20
Number150
Result30

Three calculation modes

Covers every common percentage question in one tool.

Instant results

No submit button. Results calculate as you type.

Formula shown

See the formula used so you can repeat the calculation yourself.

About this calculator

This percentage calculator covers the three questions people actually search for. The first mode answers "what is X% of Y?" — useful for working out tips, discounts, tax amounts, or commission. Type 20 and 150, get 30.

The second mode answers "X is what percentage of Y?" — for when you got 43 out of 60 on a test and want to know the score, or you want to know what fraction of a budget has been spent. Divide and multiply by 100, displayed instantly.

The third mode calculates percentage change between two values. Enter the starting value and the ending value, and it tells you whether that's an increase or decrease and by how much. The formula — (new − old) ÷ |old| × 100 — is shown below the result so you can verify the math.

All three modes show the formula used, not just the answer. If you need to explain the result to someone else (or a teacher), the working is right there.

Everything runs in your browser. No data is sent anywhere.

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Frequently Asked Questions

What is 20% of 150?

20% of 150 = 0.20 × 150 = 30. To find any percentage of a number: multiply by the percentage divided by 100.

How do I calculate a percentage increase?

((New − Old) ÷ Old) × 100. Price from $80 to $100: ((100−80) ÷ 80) × 100 = 25% increase.

What's the difference between percentage and percentage points?

Percentage is a ratio. Percentage points measure the arithmetic difference between two percentages. Interest going from 2% to 3% is 1 percentage point but a 50% rate increase.

How do I work backwards from a percentage?

Original = Result ÷ (Percentage ÷ 100). If 25% of a number is 50: 50 ÷ 0.25 = 200.

Percentage guides