Percentage Calculator
Find percentages, ratios and percent change instantly.
How to use
- Choose the mode you need at the top: what is X% of Y, X as a percentage of Y, or percent change from X to Y.
- Enter the two values for the current mode — results update in real time as you type, with no button to press.
- Each result is shown in its own card; click "Copy result" to copy the full set of numbers for the current mode.
- Each mode keeps its own inputs, so you can switch back and forth to compare results.
FAQ
What does "what is X% of Y" mean?
It finds X percent of the number Y, for example 15% of 200: 200 × 15 ÷ 100 = 30. Useful for discounts, commissions, tips and interest.
How is "X as a percentage of Y" calculated?
Divide X by Y and multiply by 100: 30 ÷ 200 × 100% = 15%, meaning 30 is 15% of 200. The denominator Y cannot be 0.
What is the difference between percent change and a ratio?
Percent change measures relative change using the starting value X as the base: (Y − X) ÷ X × 100%. A positive result means growth, a negative one means decline — a different concept from a simple ratio.
How many decimal places do results keep?
Regular numbers show up to 6 decimal places with trailing zeros removed and thousands separators added; percentages keep up to 4 decimal places for readability. All values are rounded to a sensible precision, safe for everyday use.