Percentage Calculator
Free online percentage calculator: find the percentage of a number, calculate percent change (increase or decrease), and work out what percent X is of Y - with the formula and instant results.
Result
30
About Percentage Calculator
Solve the three most common percentage problems in one place: find the percentage of a number (what is 15% of 200?), work out percent change between two values (increase or decrease), and find what percent one number is of another (X is what % of Y?). Enter your numbers and the answer appears instantly - useful for tips, discounts, taxes, grades, and quick everyday math. Everything runs in your browser.
How to Use Percentage Calculator
- Choose the calculation mode: '% of a number', '% change', or 'X is what % of Y'.
- Enter your values in the two fields.
- Read the computed result instantly - no button to press.
- Switch modes to solve a different type of percentage problem.
Percentage Calculator Examples
Percentage of a number
15% of 200 = 30.
Percentage increase
From 80 to 100 is a 25% increase.
What percent is X of Y
30 is 15% of 200.
Tip calculation
20% of a $45 bill is a $9 tip.
Read the full guide
How to Use Percentage Calculator: Complete Guide (2026) - 5 min read
Frequently Asked Questions about Percentage Calculator
- How do I calculate a percentage?
- To find a percentage of a number, multiply the number by the percentage divided by 100. Formula: result = (percentage / 100) x number. For example, 25% of 80 = (25 / 100) x 80 = 20. Use the '% of a number' mode above to do it instantly.
- How do I use the percentage calculator?
- Pick the mode that matches your question, type the two numbers, and read the answer. Use '% of a number' for things like tips and taxes, '% change' to compare an old and new value, and 'X is what % of Y' to turn a fraction into a percentage.
- What is the difference between percent of a number and percent change?
- "Percent of a number" finds a portion - e.g. 15% of 200 = 30. "Percent change" calculates how much something increased or decreased between two values - e.g. from 80 to 100 is a 25% increase. "X is % of Y" finds what percentage one number is of another - e.g. 30 is 15% of 200.
- How do I calculate a percentage increase?
- Use the "% change" tab. Enter the original value as the starting number and the new value. The tool calculates: ((New − Old) ÷ Old) × 100. A positive result means increase; negative means decrease.
- How do I work out a tip percentage?
- Use the "% of number" tab. Enter the bill amount and the tip percentage (e.g. 15 or 20). The result is the tip amount. Add it to the original bill for the total.
- What is the formula for percentage of a number?
- Result = (Percentage ÷ 100) × Number. For example, 25% of 80 = (25 ÷ 100) × 80 = 20.
- Is this calculator accurate for VAT and sales tax?
- Yes for simple tax calculations. Enter 100 (original price) and your VAT rate (e.g. 20) in the "% of number" tab to find the tax amount (20). Add to the original for the total (120). For reverse VAT (finding pre-tax price), use the "X is % of Y" tab.