Percentage Calculator
Find X% of an amount, what percent one number is of another, or the percent change between two values, with the formula shown.
How to use
- Pick a mode at the top: ‘Percent of’, ‘Share of’ or ‘Change rate’.
- ‘Percent of’ takes an amount and a %, ‘Share of’ takes a part and a whole, and ‘Change rate’ takes a before and an after value. Decimals are fine.
- The result and the formula appear instantly. A change rate is shown with + for a rise and - for a fall.
- Copy result copies the sentence, and Share with inputs copies a link with your numbers filled in.
FAQ
What is 15% of 10,000?
Use ‘Percent of’ with 10000 as the amount and 15 as the %: the result is 1,500. The formula is amount × % ÷ 100.
What percent is 30 of 200?
Use ‘Share of’ with 30 as the part and 200 as the whole: the result is 15%. The formula is part ÷ whole × 100.
How many percent is 100 rising to 130?
Use ‘Change rate’ with 100 as Before and 130 as After: the result is +30%. The formula is (after − before) ÷ before × 100.
A price falls from 50,000 to 35,000. What is the percent decrease?
‘Change rate’ with 50000 and 35000 gives -30%. The minus sign means the value fell, so the decrease, or discount, is 30%.
How much must I raise a value to undo a 20% drop?
By 25%. 100 falling to 80 is -20%, but 80 rising back to 100 is +25% because the base is now 80. A percent change depends on the starting value, so a rise and a fall of the same size do not cancel.
Why is the change rate negative?
When the second number is smaller than the first, the value decreased, so the result carries a minus sign and the word ‘decrease’. -20% means down 20%.
What happens if the base is 0?
A percentage cannot be taken of 0, so a message appears. This applies to a Before value of 0 in ‘Change rate’ and a Whole of 0 in ‘Share of’.
How do I add or subtract 10% from an amount?
Use ‘Percent of’ to get 10% of 10,000, which is 1,000, then add it (11,000) or subtract it (9,000) yourself. The calculator only returns the percent part.