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12.5% as a fraction

Per cent means out of 100: 12.5% is 12.5/100. Clear the decimal to get 125/1,000, then simplify to 1/8.

The answer

12.5% = 1/8

How to write 12.5% as a fraction

Per cent means out of 100, so write the percentage over 100: 12.5% = 12.5/100.

A fraction should have whole numbers on top and bottom, so multiply both by 10: 12.5/100 = 125/1,000.

Simplify by dividing the top and bottom by the same number. In one go, divide by the highest common factor, 125: 125/1,000 = 1/8.

If you cannot spot 125, smaller steps get there too:

  1. Divide by 5: 25/200
  2. Divide by 5: 5/40
  3. Divide by 5: 1/8

1 and 8 share no factor except 1, so 1/8 is the simplest form.

As a decimal, 12.5% = 0.125: divide by 100, which moves each digit two places to the right.

To check, divide back: see 1/8 as a decimal and 1/8 as a percentage.

Using 1/8 to find 12.5% of an amount

Knowing that 12.5% is 1/8 makes finding 12.5% of an amount quick: divide by 8.

12.5% of 40 = 40 ÷ 8 = 5

The bar model below opens on 12.5% of 40 and reaches the same answer another way, by working out 50% as half of 40, then 25% as half of 50%, then 12.5% as half of 25%. Change the numbers to try your own. Its bar is marked in tenths, so 12.5% stops partway through a tenth; the picture of 1/8 further down shows it exactly.

A bar model that finds a percentage of any amount, step by step. 12.5% of 40 is 5.

See 1/8

The bar is cut into 8 equal parts and 1 is shaded.

More percentages as fractions

Questions parents ask

What is 12.5% as a fraction?

12.5% = 12.5/100 = 125/1,000 = 1/8 in its simplest form.

What is 12.5% as a decimal?

12.5% = 0.125. Divide by 100: the digits move two places to the right.

How do you find 12.5% of an amount?

12.5% is 1/8, so divide by 8. For 12.5% of 40: 40 ÷ 8 = 5.

Fractions, decimals and percentages run all through 11+ maths

Converting between them turns up in 11+ questions on percentages, ratio, money and data. The free diagnostic checks maths, English and both kinds of reasoning, and shows what to practise next. No card is required.