% Percentage Calculator – Calculate Percent Free

Free percentage calculator. Work out what percent of a number is, find percentage change (increase or decrease), calculate percentage difference, reverse percentage and more. Six calculation types — fast and easy for students and professionals worldwide.

Percentage Calculator

Six types of percentage calculations — all free, all instant

1 What is X% of Y?

What is % of ?
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2 X is what % of Y?

is what % of ?
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3 Percentage Change (Increase / Decrease)

From to
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4 Increase / Decrease a Number by %

increased by %
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5 Reverse Percentage — Find the Original Number

is % of what number?
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6 Percentage Difference Between Two Numbers

Between and
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How to Calculate Percentages – Complete Guide

This calculator solves all six common percentage problems in one place. No need to remember formulas — just enter your numbers and get the answer instantly.

1. What is X% of Y?

Multiply Y by X and divide by 100. Example: 15% of 200 = (200 × 15) ÷ 100 = 30. Use this for tips, discounts, tax amounts and commission calculations.

2. X is What % of Y?

Divide X by Y and multiply by 100. Example: 30 is what % of 150 = (30 ÷ 150) × 100 = 20%. Use this for exam scores, survey results and proportions.

3. Percentage Change

Subtract old from new, divide by old, multiply by 100. Example: from 80 to 100 = ((100−80) ÷ 80) × 100 = +25%. Use this for price changes, growth rates and performance tracking.

4. Increase / Decrease by %

To increase: multiply by (1 + percent/100). To decrease: multiply by (1 − percent/100). Example: 200 increased by 15% = 200 × 1.15 = 230.

5. Reverse Percentage

Divide the value by the percentage and multiply by 100. Example: 85 is 70% of what? = (85 ÷ 70) × 100 = 121.43. Use this when you know the result and percentage but need the original.

6. Percentage Difference

Divide the absolute difference by the average of both numbers, multiply by 100. Example: between 40 and 60 = (|60−40| ÷ ((40+60)÷2)) × 100 = 40%. Used when neither value is the reference point.

Percentage Calculator – Used Worldwide for School, Work and Shopping

Percentages are used in every country in the world — from calculating VAT (UK), GST (Australia, Canada, India), sales tax (USA) and other consumption taxes, to working out exam scores, discounts, pay rises, investment returns and tip amounts.

Common Percentage Questions This Calculator Solves

  • What is 20% of 500? → Type 20 and 500 into Block 1
  • 15 is what percent of 60? → Use Block 2
  • Percentage increase from 80 to 100? → Use Block 3
  • What is 350 plus 15%? → Use Block 4
  • Price was £120 after 20% discount — what was original price? → Use Block 5

Percentage vs Percentile

A percentage expresses a number as a fraction of 100. A percentile shows the value below which a given percentage of observations fall — used in test scores, growth charts and statistical analysis. This calculator handles percentage calculations. For percentile calculations, see your specific test or assessment guidelines.

Frequently Asked Questions

What is the difference between percentage change and percentage difference? +
Percentage change has a clear direction — from an old value to a new value (increase or decrease). Percentage difference is used when there is no old/new relationship — it measures how different two values are relative to their average. Use percentage change for before/after comparisons and percentage difference for comparing two independent values.
How do I calculate a tip? +
Use calculator 1 — "What is X% of Y?". Enter the tip percentage (e.g. 15) and the bill amount. For a 5 bill with 15% tip: 15% of 85 = 2.75 tip, total = 7.75.
How do I calculate a discount? +
Use calculator 4 — "Decrease a number by %". Enter the original price and the discount percentage. For a 20 item with 25% off: 120 decreased by 25% = 0.
How do I find the original price before a discount? +
Use calculator 5 — "Reverse Percentage". If an item costs 5 after a 25% discount, enter 75 is 75% of what? Answer: 00 was the original price.