20% as a fraction
Per cent means out of 100: 20% is 20/100, which simplifies to 1/5.
The answer
20% = 1/5
How to write 20% as a fraction
Per cent means out of 100, so write the percentage over 100: 20% = 20/100.
Simplify by dividing the top and bottom by the same number. In one go, divide by the highest common factor, 20: 20/100 = 1/5.
If you cannot spot 20, smaller steps get there too:
- Divide by 10: 2/10
- Divide by 2: 1/5
1 and 5 share no factor except 1, so 1/5 is the simplest form.
As a decimal, 20% = 0.2: divide by 100, which moves each digit two places to the right.
To check, divide back: see 1/5 as a decimal and 1/5 as a percentage.
Using 1/5 to find 20% of an amount
Knowing that 20% is 1/5 makes finding 20% of an amount quick: divide by 5.
20% of 40 = 40 ÷ 5 = 8
The bar model below opens on 20% of 40 and reaches the same answer another way, by working out 10% as 40 ÷ 10, then 20% as 2 × 10%. Change the numbers to try your own.
A bar model that finds a percentage of any amount, step by step. 20% of 40 is 8.
See 1/5
More percentages as fractions
Questions parents ask
What is 20% as a fraction?
20% = 20/100 = 1/5 in its simplest form.
What is 20% as a decimal?
20% = 0.2. Divide by 100: the digits move two places to the right.
How do you find 20% of an amount?
20% is 1/5, so divide by 5. For 20% of 40: 40 ÷ 5 = 8.
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