how big is 3/8 inch

June 28, 2026 • 1 min read

3/8 inch is 0.375 inches, which is about 9.525 mm and a little under 1 centimeter.

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Quick Scoop

In decimal: 0.375 in.
In metric: 9.525 mm.
Ruler location: It is the third 1/8 mark after 0.

Easy Visual

Think of it as a small gap—roughly the width of a standard pencil line area or a bit less than a centimeter.

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Measurement	Approximate size
3/8 inch	9.525 mm
3/8 inch	0.375 in

If you want, I can also show you where 3/8 inch sits on a ruler with a simple text diagram.

Murugan

Written by Murugan

"The more that you read, the more things you will know. The more that you learn, the more places you'll go." — This philosophy guides my writing and exploration of ideas.