What is 0.125 as a fraction?

0.125 as a fraction is 1/8. Write the digits over 1,000 to get 125/1,000, then divide top and bottom by 125.

What is 0.125 as a percentage?

0.125 is 12.5%. Multiplying a decimal by 100 moves the point two places to the right.

How many millimetres is 0.125 of an inch?

0.125 inches is 3.175 mm, using the exact definition 1 inch = 25.4 mm.

0.125 as a fraction

Fraction1/8lowest terms

Decimal0.125

Percent12.5%

How to get there

0.125 has 3 digits after the point, so it is that many thousandths: write the digits over 1,000 — 125/1,000.
125 and 1,000 share a greatest common divisor of 125. Divide both by it: 1/8.

1 of 8 equal parts filled.

As a measurement

Read as inches, 0.125″ is 3.175 mm exactly. The nearest marks on a rule:

Rule	Nearest mark	Inches	mm	Difference
16ths	1/8″	0.125	3.175	exact
32ths	1/8″	0.125	3.175	exact
64ths	1/8″	0.125	3.175	exact

Common questions

What is 0.125 as a fraction?: 0.125 as a fraction is 1/8. Write the digits over 1,000 to get 125/1,000, then divide top and bottom by 125.
What is 0.125 as a percentage?: 0.125 is 12.5%. Multiplying a decimal by 100 moves the point two places to the right.
How many millimetres is 0.125 of an inch?: 0.125 inches is 3.175 mm, using the exact definition 1 inch = 25.4 mm.

The same number, other ways

1/8Everything about the fraction: equivalents, the bar model, the number line.12.5%The same value as a percentage, with its own derivation.Decimal → fraction chartThe whole lookup table, printable.Nearest fractionMatch 0.125″ against any rule, with the exact error.

Where this comes from. Exact rational arithmetic on the values shown — fractions are pairs of integers until display, and inch–metric conversion uses 25.4 mm to the inch, exact by definition since 1959. See the full methodology.