Percentage Calculator

Comprehensive all-in-one percentage math suite: calculate percentages of numbers, percentage change, reverse percentages, discounts, tips, VAT & taxes, and fraction conversions instantly with step-by-step formulas.

Formula 1 P% × X

What is P% of X?

Find the exact fractional value of any percentage.

Result
30
(20 / 100) × 150 = 30
Part: 30 Remainder: 120
Formula 2 (X / Y) × 100%

X is what % of Y?

Find the ratio of a part to a total as a percentage.

Result (%)
25%
(45 / 180) × 100% = 25%
Ratio: 1 / 4 Decimal: 0.25
Formula 3 (Reverse) X ÷ (P / 100)

X is P% of what?

Calculate the whole/base number from a known percentage.

Whole Number Result
250
50 ÷ (20 / 100) = 250
Verification: 20% of 250 = 50

Common Percentages & Fraction Conversion Chart

Quick mental math lookup table for standard percentages, fractions, and decimals.

Standard Math Reference
Percentage Fraction Decimal Example (of 100) Example (of 200)
1%1/1000.0112
5%1/200.05510
10%1/100.101020
12.5%1/80.12512.525
15%3/200.151530
20%1/50.202040
25%1/40.252550
33.33%1/30.333...33.3366.67
50%1/20.5050100
66.67%2/30.666...66.67133.33
75%3/40.7575150
80%4/50.8080160
90%9/100.9090180
100%1/11.00100200

How Percentages Work: Formulas & Real-World Guides

A percentage is a dimensionless ratio expressed as a fraction of 100 (from Latin per centum, meaning "by the hundred"). Understanding how to manipulate percentages is one of the most practical everyday math skills.

Margin vs. Markup in Business

Markup is the percentage added to the cost price to determine the selling price: Markup% = ((Sell - Cost) / Cost) * 100.

Profit Margin is the percentage of the selling price that is profit: Margin% = ((Sell - Cost) / Sell) * 100. A 50% markup equals a 33.3% profit margin.

Compound Percentage Changes

Percentage changes cannot simply be added together. If a stock drops by 50% and then rises by 50%, you do not break even — you end with only 75% of your original investment: 100 * 0.50 * 1.50 = 75 (a 25% net loss).

Frequently Asked Questions

Was this tool helpful?

Comments

Loading comments...

Check Out Other Popular Tools