Percentage Calculator
Calculate X% of a number, a percentage share, percentage change or a discount. See the formula and result instantly, directly in your browser.
15% of 240 is 36.
How it works
How to use the Percentage Calculator
A percentage compares a quantity with a chosen base. The calculator handles the arithmetic, while the explanation below helps you choose the fields that answer your question. Start by identifying the whole or the original value, then select the matching calculation above.
Choose the calculation that matches your numbers
Use “X% of a number” when you know the percentage and want the corresponding amount. If you already know the part and the whole, select “X is what % of Y?” instead. The change mode compares an original value with a new one. Discount mode subtracts a percentage from an original price and shows the final price as its main result.
The same pair of values can answer different questions. Entering 27 as the part and 180 as the whole gives 15%. Asking for 27% of 180 gives 48.6. Read the sentence below the result before copying it, especially if you switched modes while comparing several figures.
| Question | Mode | Worked result |
|---|---|---|
| What is 15% of 360? | X% of a number | 54 |
| 27 is what percentage of 180? | X is what % of Y? | 15% |
| What is the change from 80 to 92? | Percentage change | 15% increase |
| What is 25% off a price of 64? | Discount & final price | 48, with 16 saved |
The percentage formula and a quick mental check
To find a percentage of a value, multiply the value by the percentage and divide by 100. For 15% of 360, the calculation is 360 × 15 ÷ 100 = 54. The result keeps the original unit: 54 items, 54 kilometres or an amount of 54 in the currency you started with.
A rough check can catch an extra zero. Ten percent of 360 is 36, and five percent is half of that, or 18. Their sum is 54. When you work backwards from a known part, divide the part by the whole and multiply by 100. For example, 54 ÷ 360 × 100 returns 15%.
Percentage change and percentage points
Relative change uses the original value as the denominator: (new value − original value) ÷ original value × 100. Moving from 80 to 92 is a 15% increase. Reversing the comparison gives a decrease of about 13.043478%, because the starting value is now 92. The change is 12 in either direction, but the base is different.
When the original figures are themselves percentages, also consider percentage points. A rate moving from 30% to 36% rises by six percentage points. Its relative increase is 20%. Use the change mode with 30 and 36 for the relative figure; subtract the rates directly to describe the percentage-point difference.
Discounts, final prices and successive reductions
A 25% discount on 64 saves 16 and leaves 48 to pay for the item. Discount mode shows 48 prominently and states the saving below it. Enter the amount to which the discount actually applies. Delivery charges or excluded items may need a separate calculation.
Apply successive reductions in order. A price of 200 reduced by 10% becomes 180. Reducing that new price by another 10% leaves 162, so the total reduction is 19%. Adding the two discount percentages would give the wrong answer because the second calculation starts from a smaller price.
Enter decimals and interpret the displayed precision
A decimal point or decimal comma is accepted. Both 7.5 and 7,5 mean seven and a half. Leave out thousands separators: type 2500 when you mean two thousand five hundred. The entry 2,500 is interpreted as the decimal value 2.5. Spaces, exponent input and mixed separators are rejected so an ambiguous entry is not silently rearranged.
Input values are limited to an absolute value of one trillion. Results show up to six decimal places; very small nonzero answers use scientific notation. Ordinary browser arithmetic has finite precision, and the copied result is the formatted display. Keep any required unrounded intermediate figures separately when a workflow depends on exact rounding.
Zero values, negative answers and the visual scale
A part of zero can be compared with a positive whole and gives 0%. A whole of zero cannot be used as a denominator. Percentage change also requires a positive original value in this calculator. If a quantity starts at zero, describe the original and new quantities directly rather than assigning an arbitrary increase percentage.
The ring and bar show the magnitude of the selected percentage, capped at 100%. The numerical answer retains the actual sign and full value. For a negative change, read the decrease stated in the result sentence. For a result above 100%, use the number and formula rather than estimating it from the full circle.
Common questions
Can I calculate a percentage without an account?
Yes. These calculations run in your browser and do not use a generation allowance. You can change either input and copy the formatted percentage result without signing in.
Why does a 20% increase not undo a 20% decrease?
Each percentage uses its own starting amount. A decrease of 20% takes 100 to 80. Increasing 80 by 20% adds 16, leaving 96. Restoring 100 from 80 requires a 25% increase.
How do I recover the original price after a discount?
Divide the reduced price by the remaining proportion. After 25% off, 75% remains. A reduced price of 48 divided by 0.75 gives an original price of 64. You can check it by entering 25 and 64 in discount mode.
Can a percentage be larger than 100?
Yes. A part of 150 compared with a whole of 100 is 150%. A value equal to 200% of another value is twice as large. The visual is capped, so use the numerical result for these comparisons.
Are the numbers I enter sent to Genory?
The calculator performs its arithmetic locally and does not add requests, saved presets or URL parameters containing your entries. The website retains its existing page-level analytics and advertising preferences; the calculator does not send calculation values to those services.