Percentage Calculator

Solve percentage, ratio, and change calculations with step-by-step math breakdowns and visual aids.

1. What is X% of Y?

What is% of?

Result

15% of 200 is 30

15%

Formula & Steps

Formula: Result = Y × (X / 100)

Steps: 200 × (15 / 100) = 200 × 0.15 = 30

2. X is what % of Y?

is what % of?

Result

25%

50 is 25% of 200

25%

Formula & Steps

Formula: Result = (X / Y) × 100%

Steps: (50 / 200) × 100 = 0.25 × 100 = 25%

3. % Change from X to Y

% change fromto

Result

+25%

The percentage change from 120 to 150 is +25%

Formula & Steps

Formula: Result = ((Y - X) / X) × 100%

Steps: ((150 - 120) / 120) × 100 = (30 / 120) × 100 = 25%

4. Add / Subtract %

Add or subtract% of

Add

110

Subtract

100 + 10% is 110, and 100 - 10% is 90

Formula & Steps

Add: Y + (Y × X / 100) = 100 + 10 = 110

Subtract: Y - (Y × X / 100) = 100 - 10 = 90

Everyday Percentage Problems

This calculator covers the four questions people ask most: "What is X% of Y?" (multiply Y by X/100), "X is what percent of Y?" (divide X by Y, times 100), "What is the percentage change from X to Y?" (the difference divided by the original value), and "Add or subtract a percentage from a number" (useful for tip calculations, tax, and discounts). Every result updates instantly and is computed locally.

Private & free — this tool runs entirely in your browser.