1/8 as a decimal is 0.125 and 1/8 as a percent is 12.5%. To convert, divide 1 by 8 to get the decimal, then multiply by 100 to get the percent. This page shows both conversions step by step, a diagram of 1/8, the full table of eighths, real-life examples and practice problems with answers.
In this guide
1/8 as a Decimal and Percent: Quick Answer
| Form | Value |
|---|---|
| Fraction | 1/8 (one eighth) |
| Decimal | 0.125 |
| Percent | 12.5% |
| Decimal type | Terminating |
| Simplest form | Yes, 1/8 is already in simplest form |
What Does 1/8 Mean?
The fraction 1/8, read as “one eighth”, means one of eight equal parts, like one slice of a pizza cut into eight. Eighths are common in measuring, especially inches.
The top number, 1, is the numerator: how many parts you have. The bottom number, 8, is the denominator: how many equal parts make one whole. A fraction bar also means “divided by”, so 1/8 is the same as 1 ÷ 8. That is the key to converting it.
How to Convert 1/8 to a Decimal
Method 1: Divide the numerator by the denominator
Divide 1 by 8. Because 1 is smaller than 8, the answer starts with 0 and a decimal point, and you bring down zeros:
- 10 ÷ 8 = 1, remainder 2
- 20 ÷ 8 = 2, remainder 4
- 40 ÷ 8 = 5, remainder 0
The remainder is 0, so the division stops: 1/8 = 0.125.
Method 2: Make the denominator a power of 10
Multiply the top and bottom by the same number so the denominator becomes 10, 100 or 1000. Here 8 × 125 = 1000, so 1/8 = (1 × 125)/(8 × 125) = 125/1000 = 0.125. The number of zeros in 1000 tells you the number of decimal places.
In short: Divide 1 by 8. 1/8 = 0.125, a terminating decimal.
How to Convert 1/8 to a Percent
Method 1: Convert to a decimal, then multiply by 100
Take the decimal and multiply by 100, which moves the decimal point two places to the right: 0.125 × 100 = 12.5%.
Method 2: Multiply by 100 first, then divide
Multiply the numerator by 100 and divide by the denominator: 1 × 100 = 100, and 100 ÷ 8 = 12.5%.
Method 3: Use the value of one part
Each 1/8 is worth 12.5%. You have 1 of those parts, so 1/8 = 1 × 12.5% = 12.5%. This is the fastest way to work out any fraction with a denominator of 8 in your head.
In short: Multiply 1/8 by 100: 1/8 = 12.5%.
All Eighths as Decimals and Percents
These are the fractions with a denominator of 8. Learning the whole row makes 1/8 easier to remember, because each one is 12.5% more than the one before.
| Fraction | Decimal | Percent |
|---|---|---|
| 1/8 | 0.125 | 12.5% |
| 2/8 = 1/4 | 0.25 | 25% |
| 3/8 | 0.375 | 37.5% |
| 4/8 = 1/2 | 0.5 | 50% |
| 5/8 | 0.625 | 62.5% |
| 6/8 = 3/4 | 0.75 | 75% |
| 7/8 | 0.875 | 87.5% |
| 8/8 = 1 | 1 | 100% |
Related conversions: 1/5 as a percent and decimal, 5/8 as a percent and decimal, 7/8 as a percent and decimal.
How to Use 1/8 in Real Life
Example: Find 1/8 of 48. Divide by 8, then multiply by 1: 48 ÷ 8 = 6, and 6 × 1 = 6.
Example: Find 12.5% of 240. It is the same as 1/8 of 240: 240 ÷ 8 × 1 = 30.
- Pizza: one slice of an 8-slice pizza is 12.5% of it.
- Measuring: 1/8 inch is 0.125 inch on a ruler or drill bit.
- Cooking: 1/8 cup is 2 tablespoons.
To find any fraction of a number, divide by the bottom number and multiply by the top. For other percentage problems, see how to calculate a percentage.
Is 1/8 More Than Half?
No. 1/8 = 12.5%, which is less than 50%. The part that is left over is 7/8, which is 87.5%, because 12.5% + 87.5% = 100%.
How to Convert the Decimal or Percent Back to 1/8
Write the decimal over a power of 10, then simplify. 0.125 has 3 decimal places, so 0.125 = 125/1000. Divide the top and bottom by their greatest common factor, 125: 125 ÷ 125 = 1 and 1000 ÷ 125 = 8. So 0.125 = 1/8.
From the percent: 12.5% = 12.5/100. Multiply top and bottom by 10 to clear the decimal, then simplify the same way.
Equivalent fractions of 1/8: 2/16, 3/24, 4/32 and 5/40. They all equal 0.125 and 12.5%.
Common Mistakes When Converting 1/8
- Rounding 12.5% to 12% or 13% too early. 1/8 is exactly 12.5%, so keep the half percent.
- Dividing the wrong way round. 1/8 means 1 ÷ 8, not 8 ÷ 1. 8 ÷ 1 = 8, which is more than 1.
- Forgetting to multiply by 100. 0.125 is the decimal. The percent is 100 times bigger: 12.5%.
- Moving the decimal point the wrong way. To go from decimal to percent, move it two places to the right.
1/8 Practice Problems (With Answers)
1. Write 3/8 as a decimal and a percent.
0.375 and 37.5%. Divide 3 by 8, then multiply by 100.
2. What is 1/8 of 96?
12. 96 ÷ 8 × 1 = 12.
3. What percent is 7 out of 56?
12.5%. 7/56 simplifies to 1/8.
4. A tank holds 80 litres and is 1/8 full. How many litres are in it, and what percent full is it?
10 litres, 12.5% full.
5. Write 37.5% as a fraction in simplest form.
3/8.
1/8 as a Percent and Decimal: FAQ
What is 1/8 as a decimal?
1/8 as a decimal is 0.125. Divide 1 by 8 to get it.
What is 1/8 as a percent?
1/8 as a percent is 12.5%. Multiply the decimal by 100 to get it.
How do you convert 1/8 to a percentage?
Divide 1 by 8 to get 0.125, then multiply by 100 and add the % sign. Or multiply 1 by 100 first: 100 ÷ 8 = 12.5%.
Is 1/8 a terminating or repeating decimal?
1/8 is a terminating decimal. It stops after 3 decimal places, because its denominator, 8, has no prime factors other than 2 and 5.
What fractions are equal to 1/8?
2/16, 3/24 and 4/32 are all equal to 1/8, because each is 1/8 with the top and bottom multiplied by the same number.
Sources and Further Reading
- OpenStax, Prealgebra 2e, Section 6.1: Understand Percent, Rice University.
- Math is Fun, Convert Fractions to Decimals.
- Math is Fun, Convert Fractions to Percents.
Every value on this page was checked by exact division. Convert any number with the percentage calculator or the CalcSolver calculator, and browse all percentage and decimal guides.
Related: browse all percentages and decimals guides, or use the equivalent fractions calculator for fractions.
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