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Percentage calculator

Find X% of Y, what percent one number is of another, and percentage increase, decrease and change, with the working shown.

Type in any card — results and working update instantly.

Percent of a number

What is
%
of
?
30
Working
  1. 15% = 15 ÷ 100 = 0.15
  2. 0.15 × 200 = 30

What percent is it?

is what % of
?
25%
Working
  1. 30 ÷ 120 = 0.25
  2. 0.25 × 100 = 25%

Find the whole

is
%
of what?
250
Working
  1. 18% = 0.18
  2. 45 ÷ 0.18 = 250

Percentage change

From
to
+25%increase
Working
  1. Difference: 100 − 80 = 20
  2. 20 ÷ |80| = 0.25
  3. × 100 = 25%

Increase or decrease by a percent

by
%
280+30
Working
  1. 12% of 250 = 30
  2. 250 + 30 = 280
  3. Shortcut: 250 × 1.12 = 280

Reverse percentage (original value)

is the result of a
%
. Original?
135
Working
  1. Multiplier = 1 − 0.2 = 0.8
  2. 108 ÷ 0.8 = 135
  3. Check: 135 − 20% = 108

Percentage difference

Between
and
40%
Working
  1. |40 − 60| = 20
  2. Average: (40 + 60) ÷ 2 = 50
  3. 20 ÷ 50 × 100 = 40%
  4. Unlike percentage change, the order of A and B doesn't matter.

Percentage points

From
%
to
%
+0.75 pp+16.67% relative
Working
  1. Points: 5.25 − 4.5 = 0.75 percentage points
  2. Relative change: 0.75 ÷ 4.5 × 100 = 16.67%
Runs in your browser · no uploadHow it works

How to use Percentage calculator

  1. 1

    Find the right card

    Pick the card that matches your question, such as percent of a number, percentage change or reverse percentage.

  2. 2

    Type your numbers

    Fill in the boxes inside the sentence; for increases and decreases, choose the direction with the toggle.

  3. 3

    Read the answer and the working

    See the result in large type, copy it with one tap, and follow the numbered steps below it.

Limits and Pro

Free and unlimited: eight calculators on one page, values up to ±1,000,000,000,000,000 and results shown with 0 to 6 decimal places.

About Percentage calculator

Eight percentage calculators sit side by side on this page, each written as the question people actually ask, with boxes to fill in: what is 15% of 200; 30 is what percent of 120; 45 is 18% of what; the percentage change from 80 to 100; increase or decrease 250 by 12%; the original value before a change that produced 108; the percentage difference between 40 and 60; and the change from 4.5% to 5.25% in percentage points. Each card shows the answer in large type with a copy button, and the working underneath, step by step, so you can check the logic or copy it into homework.

The cards cover the everyday jobs percentages do. Shoppers can take a discount off a price or recover the price before a sale or before VAT was added. Investors and analysts can measure growth between two figures, and journalists can tell a rise of half a percentage point from a 12% relative increase — a distinction that changes how an interest-rate or poll story reads. Teachers can turn marks into percentages, and anyone splitting costs can find what share each person is paying.

Results respect your browser's number format, and a single setting chooses how many decimal places to show, from whole numbers up to six places. The two formulas people mix up most — percentage change, which depends on which value you start from, and percentage difference, which compares two values symmetrically — are labelled clearly. Inputs are kept in the address, so a link reproduces every card exactly.

Privacy

Every percentage is computed in your browser; the numbers you type are never sent to a server. They're kept in the page address so a link reproduces your calculation, and in local storage on this device.

Features

Working shown

Every card lists the steps behind its answer.

Reverse percentages

Find the price before a discount, VAT or a raise.

Points vs percent

Percentage-point and relative change side by side.

Percentage calculator: frequently asked questions

How do I calculate a percentage of a number?
Divide the percentage by 100 to turn it into a decimal, then multiply by the number. For 15% of 200: 15 ÷ 100 = 0.15, and 0.15 × 200 = 30. The same works in reverse order — 200% of 15 is also 30 — because multiplication doesn't care which comes first. The first card does this and shows the steps.
How do I work out a percentage increase or decrease?
Subtract the old value from the new one, divide by the old value and multiply by 100. Going from 80 to 100 is (100 − 80) ÷ 80 × 100 = a 25% increase. Going back from 100 to 80 is a 20% decrease, not 25%, because the starting value is now 100. The sign tells you the direction.
How do I find the original price before a discount or tax?
Divide by the multiplier rather than subtracting the percentage. If a jacket costs 108 after 20% off, the original was 108 ÷ 0.8 = 135 — taking 20% of 108 and adding it back gives the wrong 129.60. For a price of 120 that includes 20% VAT, the price before tax is 120 ÷ 1.2 = 100.
What is the difference between percentage change and percentage difference?
Percentage change measures movement from a starting value, so direction matters: from 40 to 60 is +50%, from 60 to 40 is −33.33%. Percentage difference compares two values without a starting point, dividing the gap by their average: 40 and 60 differ by 20 ÷ 50 × 100 = 40% either way. Use difference for comparing two measurements of equal standing.
What does percentage points mean?
Percentage points measure the simple gap between two percentages. If a mortgage rate rises from 4.5% to 5.25%, it has gone up 0.75 percentage points — but relative to where it started that is a 16.67% increase. Headlines often confuse the two; the last card shows both figures together so the size of the change is clear.

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