Percentage Calculator

How to use

1. Find the calculator that matches your question, for example "What is __% of __?" or "% change from __ to __".
2. Type your numbers into its boxes. The result and the formula with your numbers update as you type.
3. For Increase or decrease a number by a percentage, choose Increase or Decrease from the list first.
4. Use Round results to if you need more or fewer decimal places. A ≈ sign before a result means it was rounded for display.
5. Click Copy under a calculator to copy its answer and formula as plain text.

Examples

30   (20 ÷ 100 × 150)

25%   (30 ÷ 120 × 100)

300   (45 × 100 ÷ 15)

+25%, an increase   ((100 − 80) ÷ 80 × 100)

220   (250 × 0.88)

40%   (20 ÷ 50 × 100)

≈ 33.3333%, rounded to 4 decimal places

Supported formats

• Numbers such as 1250, 1,250.75, -12.5, .5, +3 or 2.5e6. A % sign before or after the number is ignored, and the Unicode minus sign (−) works as well as a hyphen.
• Commas are accepted only as thousands separators in groups of three. A decimal comma (12,5) is rejected with a message rather than silently read as 125.
• Results are rounded to 0 to 10 decimal places (4 by default), with trailing zeros removed and thousands separators added.

Privacy

This tool runs entirely in your browser. Nothing you enter or open is sent anywhere. Privacy policy.

Limitations

• Numbers are limited to 80 characters and exponents from e-100 to e+100. Within those limits every result is calculated exactly as a fraction and rounded only for display.
• Percentage change is undefined when the starting value is 0, so the tool shows the absolute change instead. Likewise, X is what % of 0 and X is 0% of what have no answer and are reported as errors.
• Rounding is half away from zero (2.5 → 3, −2.5 → −3). Spreadsheets that use banker's rounding can differ in the last decimal place.
• Each calculator works on one pair of numbers. For compound growth over several periods, or a chain of percentage changes, apply the steps one at a time.

FAQ

What is the difference between percentage change and percentage difference?

Percentage change has a direction: it compares a new value with an old one and divides by the old value, so 80 to 100 is a 25% increase while 100 to 80 is a 20% decrease. Percentage difference has no direction: it divides the gap by the mean of the two values, so 80 and 100 are 22.2222% apart whichever way round you enter them. Use change for before-and-after figures and difference for comparing two measurements of equal standing.

What is a percentage point?

A percentage point is the plain difference between two percentages. If an interest rate goes from 4% to 5%, it has risen by 1 percentage point, but by 25% in relative terms, because 1 is a quarter of 4. News reports mix the two up often; to get the relative figure, put 4 and 5 into the % change calculator.

Why does increasing by 20% and then decreasing by 20% not get me back where I started?

The second percentage is taken from a different base. 100 increased by 20% is 120, and 20% of 120 is 24, so decreasing gives 96. To undo an increase of p%, divide by (1 + p ÷ 100) instead: 120 ÷ 1.2 = 100. The X is Y% of what? calculator does this if you enter 120 and 120.

How is a change from a negative number handled?

The change is divided by the size of the starting value (its absolute value), so moving upwards is always reported as an increase. For example, −50 to −25 is a 50% increase. Some textbooks divide by the signed value instead, which flips the sign; percentage changes on numbers that cross zero are hard to interpret either way.

Why do other calculators show 0.30000000000000004?

Most software stores numbers in binary floating point, which cannot hold 0.1 exactly, so small errors appear in the last digits. This tool reads what you type as an exact decimal fraction and keeps it exact through the calculation, so 0.1% of 300 is exactly 0.3.

Is anything I type sent to a server?

No. The calculations run in this page's JavaScript and nothing is uploaded or stored.

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