Percentage Calculator — 4 Modes, Free & Instant
Four percentage calculators in one: find % of a number, calculate % change, determine what % X is of Y, or adjust a value by any percentage. Free.
What is this calculator?
This percentage calculator computes four common percentage scenarios: what is X% of Y, what percent is X of Y, percentage change from X to Y, and percentage increase or decrease of Y by X%. The underlying concept is that a percentage represents a fraction of 100, allowing proportional comparisons between values.
Formula
For 'percent of': result = (X/100) * Y. For 'is what percent': result = (X/Y) * 100. For 'percent change': result = ((Y - X) / X) * 100. For 'percent adjust': result = Y * (1 ± X/100), where + is increase and - is decrease.
Example
To find 15% of 200, set mode to 'percent-of', a=15, b=200. The result is 30. To find what percent 30 is of 200, set mode to 'is-what-percent', a=30, b=200; result is 15%.
How to use
- 1Select the calculation mode from the dropdown: 'percent-of', 'is-what-percent', 'percent-change', or 'percent-adjust'. Then enter the first value (X) and second value (Y) in the number fields.
- 2Click the Calculate button. The calculator applies the appropriate formula based on the selected mode and computes the result, rounding it to two decimal places.
- 3The output shows the raw result and the rounded result. For 'percent-change' mode, it also indicates whether the change is an increase (positive) or decrease (negative). Use the rounded result for practical purposes.