Percentage Calculator

About this tool

This calculator covers the four percentage calculations people need most often: finding a percentage of a number, working out what percentage one number is of another, and applying a percentage increase or decrease. Results update as you type — there's no calculate button to press.

Examples:

• X% of Y — 15% of 1250 is 187.5. Useful for tips, discounts, and commissions.
• X is what % of Y — 45 is 18% of 250. Useful for working out a proportion or a pass rate.
• Increase by X% — 1250 increased by 15% is 1437.5. Useful for markups and rate rises.
• Decrease by X% — 1250 decreased by 15% is 1062.5. Useful for discounts and depreciation.

Frequently asked questions

What happens if I divide by zero?

In "X is what % of Y" mode, if Y is 0 the calculator shows "N/A" instead of an error, since the calculation is undefined.

Does this round the result?

Results are shown to two decimal places for readability. The underlying calculation is not rounded before display.

Can I use negative numbers?

Yes — negative values are accepted and calculated normally, which is useful for reversals or decreases expressed as negative percentages.