What is 3/10 as a decimal?

3/10 is exactly 0.3 as a decimal.

How many millimetres is 3/10 of an inch?

3/10 of an inch is 7.62 mm, computed with the exact definition 1 inch = 25.4 mm.

3/10

Fraction3/10

Decimal0.3

Percent30%

3 of 10 equal parts filled — the same share as a bar and as a circle.

Where the decimal comes from

3/10 equals 0.3.

The denominator is already a power of ten, and that is what a decimal is: 0.3 means 3 tenths.

30 of 100 squares — 0.3 of the whole. The same squares read as a percentage: 30%, because percent means per hundred.

Every way to write it

Decimal: 0.3
Percent: 30%
Ratio: 3 : 10 (part to whole)
As inches: 3/10″ = 7.62 mm

Equivalent fractions

Multiply the top and bottom of 3/10 by the same number and the value does not change:

3/10 = 6/20 = 9/30 = 12/40 = 15/50 = 18/60 · more, or pick a denominator

On the number line

As a measurement

Read as inches, 3/10″ is 7.62 mm exactly. The nearest marks on the finer rules:

Rule	Nearest mark	Decimal inches	mm	Difference
16ths	5/16″	0.3125	7.9375	+0.3175 mm
32ths	5/16″	0.3125	7.9375	+0.3175 mm
64ths	19/64″	0.296875	7.5406	−0.0794 mm

Need a different rule or a tolerance? Nearest fraction · Within tolerance

Common questions

What is 3/10 as a decimal?: 3/10 is exactly 0.3 as a decimal.
What is 3/10 as a percentage?: 3/10 is exactly 30%.
How many millimetres is 3/10 of an inch?: 3/10 of an inch is 7.62 mm, computed with the exact definition 1 inch = 25.4 mm.

Fraction–decimal chartThe everyday set, printable.Rule charts16ths, 32nds, 64ths, 128ths.The rulerSee 3/10 in its place.

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.