Percentage Calculator
With percentage 10 percent, of this amount 100, or, this amount as a percentage of it 50, percentage comes to 10.00 — result. It is reached in 5 steps, the last of which is 10 / 100 * 100, and each one is printed on the page with its numbers filled in. The formula is the one published by NIST Engineering Statistics Handbook, not an approximation fitted to it.
What X% of a number is, plus the discounted price, the marked-up price and the remainder.
Formula and sources checked · How we check
Percentage 10, Of this amount 100, Or, this amount as a percentage of it 50
10.00
Result for the inputs in this link. Editing a field recomputes the calculator below; this figure holds the answer the page was loaded with.
It is written into the HTML rather than drawn by a script, so a search engine reading this page without running JavaScript still finds an answer.
- That percentage of the amount
10 / 100 * 10010- The second amount as a percentage of the first
50 / 100 * 10050 %- What is left
100 - 1090- The amount increased by it
100 + 10110- If the amount is that percentage of a larger number, that number is
100 / 10 * 1001,000
Worked example
20% of 250 is 50, leaving 200 after a discount and giving 300 after a markup. Note the asymmetry: a 20% discount then a 20% markup returns 240, not 250, because each percentage applies to a different base.
How to work it out yourself
- 1.Enter the percentage and the amount it applies to. The answer is the part, and the remainder beside it is what is left.
- 2.The reverse line answers the other question people bring here: if this amount is that percentage, what was the whole.
- 3.Percentages commute. 8% of 25 and 25% of 8 are both 2, which is often the faster way to do it in your head.
- 4.The three questions are the same equation with a different unknown: part = percent × whole ÷ 100. Fill in the two you know and the page prints the third.
The formula
- That percentage of the amount
10 / 100 * 100 - The second amount as a percentage of the first
50 / 100 * 100 - What is left
100 - 10 - The amount increased by it
100 + 10 - If the amount is that percentage of a larger number, that number is
100 / 10 * 100
Source: NIST Engineering Statistics Handbook, US Bureau of Labor Statistics — percent-change methodology
Questions people actually ask
- Why do a discount and a markup of the same size not cancel?
- The discount comes off the original price and the markup goes on the reduced one. 250 → 200 → 240. Retail "50% off then 20% off" works the same way and lands at 40% off, not 70%.
- How do I work backwards from a discounted price?
- Divide, do not subtract. A $200 item that is 20% off started at 200 ÷ 0.80 = $250. Subtracting 20% from 200 gives $160, which is the answer to a different question.
- What is a percentage point?
- An absolute difference between two percentages. Moving a margin from 20% to 25% is 5 percentage points but a 25% relative increase — which is why financial reporting always specifies which one it means.
Related
- Percentage Change CalculatorPercentage increase or decrease between two values, with the absolute difference and the multiplier.
- Sales Tax CalculatorTax and total from a pre-tax price, plus the reverse — the pre-tax price hidden inside a total you already paid.
- Percent Off CalculatorThe sale price after a discount, after a second discount stacked on it, and after tax — with what you actually saved.
- Percent Error CalculatorPercent error against a known value, with percent difference beside it — they are different questions and get confused constantly.
- Tip CalculatorTip and total from a bill, and what each person owes once it is split — including the rounding that makes the split come out even.
- Unit Price CalculatorPrice per unit for two package sizes at once, so the bigger box can be checked rather than assumed — it is the cheaper one about four times in five, not five.
Worked out already
The same calculator with the numbers filled in. Each one computes on the server, so the answer is in the page rather than waiting on a click.
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