Percentage Calculator

How do you calculate percentages?

A percentage expresses one hundredth of a number. It comes up constantly in everyday life — discounts, VAT, interest, price hikes and statistics. This tool brings the three most commonly needed percentage calculations together on a single screen.

• Percentage of a number: number × percentage ÷ 100
• Finding a ratio: part ÷ whole × 100
• Percentage change: (new − old) ÷ old × 100

Worked examples

• What is 15% of 240? → 240 × 15 ÷ 100 = 36
• 30 is what percent of 120? → 30 ÷ 120 × 100 = 25%
• Price rose from 800 to 920 → (920 − 800) ÷ 800 × 100 = 15% increase
• Price fell from 500 to 400 → (400 − 500) ÷ 500 × 100 = 20% decrease

Common scenarios

• Discount: An item of 750 with 20% off → 750 × 0.80 = 600. Shortcut: multiply by the remaining ratio.
• Price increase: An amount of 1,200 raised by 35% → 1,200 × 1.35 = 1,620.
• Consecutive percentages: A 20% rise followed by a 20% fall does not return to the start: 100 → 120 → 96. Ratios are multiplied, not added.
• Percentage point difference: Going from 10% to 15% is a 5 point rise, but a 50% increase. The two are different things.

There is a separate tool for VAT-inclusive/exclusive amounts: VAT calculator. For profit margin, see the profit margin calculator instead.