Learn more
Calculate percentages, percentage increases, and percentage of a number instantly.
Our free percentage calculator handles the most common percentage questions: what is X% of Y, what percentage is X of Y, and percentage change between two numbers. The calculator is designed to give a fast answer, but the quality of the answer still depends on accurate inputs and a clear idea of what decision you are trying to support.
- Enter Calculation Type, First Value, and Second Value using the same units you plan to compare or report.
- Read the main result first, then use the supporting outputs to understand the trade-offs behind that result.
- Compare your numbers with the worked examples below if you want a quick reasonableness check.
The calculator switches between the most common percentage questions so you can move from raw numbers to a share, rate, or change figure quickly. On this page, the primary output is result.
Scenario 1: What is 25% of 200?. Inputs used: mode: of, valueA: 25, valueB: 200. Example result: 50. 25% of 200 = 200 × 0.25 = 50. Scenario 2: Percentage change from 80 to 100. Inputs used: mode: change, valueA: 80, valueB: 100. Example result: +25%. (100-80)/80 × 100 = 25% increase.
Core formula: percent of, percent share, or percentage change depending on mode. The calculator switches between three common percentage formulas: finding a share of a number, finding what percent one value is of another, and measuring change from one value to another.
- Percentage change uses the first value as the base.
- Formatted output adds percent signs only when the mode requires it.
Use this calculator when reviewing discounts, growth, margins, survey data, or any comparison where relative scale matters. Related paths for follow-up analysis include fraction calculator, vat calculator, and roi calculator.
Most bad outputs come from a few repeated input errors or interpretation mistakes. Use this short checklist before relying on the result.
- Using the wrong mode for the question you are trying to answer.
- Confusing percentage points with percent change.
- Using the new value as the base when the old value should be the reference.
