1 cm to Inches
1 centimeters is approximately 0.3937 inches. Change the input, copy the result, or compare the nearest 1/16-inch ruler mark and its rounding error.
Best solution
Default conversion: 1 cm is 0.3937 inches; nearest 1/16-inch mark: 3/8 in.
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Calculation for 1 cm
1 cm ÷ 2.54 = 50/127 ≈ 0.3937 in
The nearest 1/16-inch mark is 3/8 in. Its signed difference from 1 cm is -0.475 mm; positive means longer. The fraction is a ruler approximation, not the exact conversion.
One international inch is exactly 2.54 centimeters. Decimal answers are rounded to four places; ruler fractions are rounded separately to the nearest sixteenth. A displayed ruler mark is not an actual-size ruler or a tolerance guarantee. NIST unit conversion reference.
Real-World Context & Technical Standards
Width of a Standard Push Pin Head
At exactly 10 millimeters, 1 cm is roughly the diameter of a classic thumb tack or the width of a small fingernail.
Standard Office Staple Width
A standard No. 10 or 26/6 office staple measures roughly 1 to 1.2 centimeters across its top crown.
Compare nearby values
Frequently Asked Questions
What is 1 cm in inches exactly?
By international definition (1 inch = 2.54 cm), 1 cm equals exactly 50/127 inches. In decimal form, it is approximately 0.3937 inches.
What is the closest ruler fraction for 1 cm?
On a standard imperial ruler marked in sixteenths of an inch, 1 cm is closest to 3/8 in (approx -0.475 mm difference).
How do I convert 1 cm to inches manually?
Divide 1 by 2.54: 1 ÷ 2.54 = 0.3937 inches. To convert back, multiply inches by 2.54.