Maths Percentages

Percentage calculator

Percent

Answer 12

80 × 15 ÷ 100 = 12

The other part 68

Live · the formula is shown under every answer

Worked example

A €80 jacket at 15% off: 15% of 80 is 12, so you pay 68. The second row shows that remaining 68 without a second sum.

A percentage is a fraction out of a hundred. To find X% of a number, multiply by X and divide by 100. To find what percentage one number is of another, divide the first by the second and multiply by 100. Percentage change is the difference divided by the starting value, times 100.

How to use it

1 Pick the question you are actually asking from the four buttons at the top.

2 Fill in the two numbers. The answer updates as you type.

3 The mono line under the result shows the arithmetic, so you can check it or repeat it elsewhere.

Percentage points and per cent are different things, and mixing them up is the most common error in this whole area. If a rate moves from 4% to 5%, that is a rise of one percentage point and a rise of twenty-five per cent. Both statements are true and they are not interchangeable.

Questions

Why is a 25% rise not cancelled by a 25% fall? −

Because the second percentage is taken from a bigger number. Eighty up 25% is 100; a hundred down 25% is 75, not 80. Use the change mode to see it.

How do I take VAT off a gross price? +

What is a percentage point? +

Can I use it for two stacked discounts? +

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