Percentage Calculator

Solve any percentage problem in seconds: X% of a number, what percent X is of Y, or the percentage change between two values.

15% of 200
30

How this percentage calculator works

A percentage is simply a fraction of 100 — the word comes from the Latin per centum, "by the hundred". This calculator covers the three percentage problems people meet most often in daily life: finding a percentage of a number (discounts, tips, taxes), expressing one number as a percentage of another (test scores, market share), and measuring percentage change between two values (price rises, salary increases, weight loss).

The formulas

X% of Y = (X ÷ 100) × Y
X as % of Y = (X ÷ Y) × 100
% change = ((New − Old) ÷ Old) × 100

Everyday examples

  • Shopping: a $80 jacket with a 25% discount costs 80 − (25 ÷ 100 × 80) = $60.
  • Tipping: an 18% tip on a $46 bill is (18 ÷ 100) × 46 = $8.28.
  • Finance: a stock moving from $120 to $138 has gained ((138 − 120) ÷ 120) × 100 = 15%.

All calculations run instantly in your browser — nothing you type is sent to a server.

Frequently asked questions

How do I calculate a percentage of a number?

Divide the percentage by 100 and multiply by the number. For example, 15% of 200 is (15 ÷ 100) × 200 = 30.

How do I work out what percent one number is of another?

Divide the first number by the second and multiply by 100. For example, 30 is (30 ÷ 200) × 100 = 15% of 200.

How is percentage change calculated?

Subtract the old value from the new value, divide by the old value, then multiply by 100. Going from 50 to 65 is a change of ((65 − 50) ÷ 50) × 100 = +30%.

What is the difference between percentage points and percent?

Percentage points measure the simple difference between two percentages (from 40% to 50% is 10 points), while percent change compares them relatively (that same move is a 25% increase).