Percentage calculator
Three everyday percentage identities — part of whole, percent change, and reverse — with wording that matches how people actually search.
Defaults to your region. Switch to compare any other scale.
Result
45
18% of 250
About this tool
A percentage calculator answers the everyday questions behind discounts, marks, tax add-ons, and growth rates. Use it when you need what x% of y is, what percent one number is of another, the percent change between two values, or the original amount before a percent was applied.
The three identities share the same ratio idea: part ÷ whole × 100. Percent change divides the difference by the starting value, so a rise from 80 to 100 is +25%, not +20 percentage points. Reverse percentage recovers the base when you already know the result after a markup or markdown.
Pick the mode that matches your wording, enter the two numbers you have, and read the third. Pair this tool with GST, VAT, tip, or statistics pages when the percent sits inside a larger workflow.
Formula
Percentage = (part ÷ whole) × 100Change = ((new − old) ÷ old) × 100Whole = part ÷ (percent ÷ 100)
How it is calculated
- Choose the mode.
- Fill the two known values.
- The third is computed from the matching identity.
Questions
Percent change vs points?
If a rate goes from 10% to 12%, that is a 2 percentage-point rise and a 20% relative change. This tool reports the relative change.
Is percent change the same as percentage points?
No. A rise from 10% to 12% is +2 percentage points but +20% relative change. This tool’s change mode uses the relative form.
Are the results official advice?
No. Calculate This is an educational tool. For important decisions, check primary sources or ask a qualified professional.