What is 0.18 as a fraction?

0.18 as a fraction is 9/50. Write the digits over 100 to get 18/100, then divide top and bottom by 2.

What is 0.18 as a percentage?

0.18 is 18%. Multiplying a decimal by 100 moves the point two places to the right.

How many millimetres is 0.18 of an inch?

0.18 inches is 4.572 mm, using the exact definition 1 inch = 25.4 mm.

0.18 as a fraction

Fraction9/50lowest terms

Decimal0.18

Percent18%

How to get there

0.18 has 2 digits after the point, so it is that many hundredths: write the digits over 100 — 18/100.
18 and 100 share a greatest common divisor of 2. Divide both by it: 9/50.

18 of 100 squares — 0.18 of the whole, which is also 18%.

As a measurement

Read as inches, 0.18″ is 4.572 mm exactly. The nearest marks on a rule:

Rule	Nearest mark	Inches	mm	Difference
16ths	3/16″	0.1875	4.7625	+0.1905 mm
32ths	3/16″	0.1875	4.7625	+0.1905 mm
64ths	3/16″	0.1875	4.7625	+0.1905 mm

Common questions

What is 0.18 as a fraction?: 0.18 as a fraction is 9/50. Write the digits over 100 to get 18/100, then divide top and bottom by 2.
What is 0.18 as a percentage?: 0.18 is 18%. Multiplying a decimal by 100 moves the point two places to the right.
How many millimetres is 0.18 of an inch?: 0.18 inches is 4.572 mm, using the exact definition 1 inch = 25.4 mm.

The same number, other ways

9/50Everything about the fraction: equivalents, the bar model, the number line.18%The same value as a percentage, with its own derivation.Decimal → fraction chartThe whole lookup table, printable.Nearest fractionMatch 0.18″ 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.