GSCalculate

Percentage Calculator

Calculate percentages instantly: what is X% of Y, X as a percent of Y, or percent increase and decrease. Free, clear math with no signup.

Reviewed / updated August 4, 2026

Your inputs

%

Result

15% of 240

36

Percent
15%
Of value
240
Result
36

15% of 240 equals 36.

Suggested next steps

  • Switch to “X is what % of Y?” if you know both amounts and need the percent.
  • Use the Discount Calculator for sale-price math with a percent off.
  • Try % increase/decrease to compare an old value with a new value.

How the percentage calculation works

This tool supports three everyday percentage problems:

  1. What is X% of Y? → result = (X ÷ 100) × Y
  2. X is what % of Y? → percent = (X ÷ Y) × 100
  3. Percent change → ((new − old) ÷ |old|) × 100

Pick a mode, enter the two numbers, and the result updates immediately — no submit button. Rule-based tips explain whether a share is large, whether a part exceeds the whole, and how to read increase versus decrease. Charts compare the inputs so you can see relative size at a glance.

Worked example

Mode: What is X% of Y? with X = 15 and Y = 240

  1. 15 ÷ 100 = 0.15
  2. 0.15 × 240 = 36

So 15% of 240 is 36. In “X is what % of Y?” mode, entering 36 and 240 returns 15%. If a price rises from 240 to 276, percent change = (36 ÷ 240) × 100 = 15% increase.

Methodology and notes

All math runs in your browser. Division by zero is blocked for “is what percent” and for percent change from a zero start. For money-specific percent-off problems, the Discount Calculator formats currency and optional sales tax more directly.

Frequently asked questions

Convert the percent to a decimal by dividing by 100, then multiply by the number. Example: 15% of 240 = 0.15 × 240 = 36. This calculator does that as soon as you enter both values.

Related tools

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