What is 0.04 as a fraction?

0.04 as a fraction is 1/25. Write the digits over 100 to get 4/100, then divide top and bottom by 4.

What is 0.04 as a percentage?

0.04 is 4%. Multiplying a decimal by 100 moves the point two places to the right.

How many millimetres is 0.04 of an inch?

0.04 inches is 1.016 mm, using the exact definition 1 inch = 25.4 mm.

0.04 as a fraction

Fraction1/25lowest terms

Decimal0.04

Percent4%

How to get there

0.04 has 2 digits after the point, so it is that many hundredths: write the digits over 100 — 4/100.
4 and 100 share a greatest common divisor of 4. Divide both by it: 1/25.

4 of 100 squares — 0.04 of the whole, which is also 4%.

As a measurement

Read as inches, 0.04″ is 1.016 mm exactly. The nearest marks on a rule:

Rule	Nearest mark	Inches	mm	Difference
16ths	1/16″	0.0625	1.5875	+0.5715 mm
32ths	1/32″	0.03125	0.7938	−0.2223 mm
64ths	3/64″	0.046875	1.1906	+0.1746 mm

Common questions

What is 0.04 as a fraction?: 0.04 as a fraction is 1/25. Write the digits over 100 to get 4/100, then divide top and bottom by 4.
What is 0.04 as a percentage?: 0.04 is 4%. Multiplying a decimal by 100 moves the point two places to the right.
How many millimetres is 0.04 of an inch?: 0.04 inches is 1.016 mm, using the exact definition 1 inch = 25.4 mm.

The same number, other ways

1/25Everything about the fraction: equivalents, the bar model, the number line.4%The same value as a percentage, with its own derivation.Decimal → fraction chartThe whole lookup table, printable.Nearest fractionMatch 0.04″ 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.