Solve any percentage problem in seconds. Pick the tab that matches your question, enter your numbers, and get the answer instantly.
Example: "What is 20% of 350?" — enter 20 and 350 below.
Know the result but not the percentage? Try
Convert between fractions, decimals, and percentages instantly.
Type in any field and the others update automatically.
Use this for tips, discounts, sales tax, or any "how much is X percent of Y" question.
(Percent ÷ 100) × Number
Perfect for test scores, completion rates, and "what portion is this?" questions.
(Part ÷ Whole) × 100
Tracks increase or decrease over time — prices, revenue, weight, anything measurable.
((New − Old) ÷ |Old|) × 100
If you know a number and what percentage it represents, this reveals the full amount.
(Part ÷ Percent) × 100
A percentage expresses a number as a fraction of 100. The concept is simple, but in practice people run into trouble because the same word "percentage" covers several different calculations: finding a part of a whole, figuring out what fraction one number is of another, measuring how much something has changed, or working backward from a partial value to the full amount. This calculator handles all four.
This is the most common percentage operation. You already know the percentage and the total — you need the result. Divide the percentage by 100 to convert it to a decimal, then multiply by the number. For example, 15% of 200 is 0.15 × 200 = 30. This is the math behind every tip calculation, discount, and tax amount.
This reverses the direction: you have two numbers and need to know what fraction the first is of the second, expressed as a percentage. Divide the part by the whole and multiply by 100. If you scored 38 out of 50 on a test, that's (38 ÷ 50) × 100 = 76%. The same formula applies to market share, completion rates, or any "how much of the total is this?" question.
Percentage change tells you how much a value grew or shrank relative to where it started. The formula is ((New − Original) ÷ |Original|) × 100. A positive result means increase; a negative result means decrease. This is the standard way to report revenue growth, price changes, population shifts, and anything else tracked over time. Note that the direction matters: going from 100 to 150 is a 50% increase, but going from 150 to 100 is a 33.3% decrease.
Sometimes you know a partial value and the percentage it represents, and you need the total. Divide the part by the percentage, then multiply by 100. If 30 represents 15% of a total, the total is (30 ÷ 15) × 100 = 200. This comes up when someone tells you "that's 20% of the budget" and you need to figure out the actual budget.