How many thou are in 1 inch?

One inch contains exactly 1,000 thou. This is the definition: 1 thou = 1/1,000 inch = 0.001 inches.

How do I convert inches to thou?

Multiply inches by 1,000 or move the decimal point three places right. For example, 0.062 inches = 62 thou.

What is a thou used for?

Measuring thin things in the imperial system: paint thickness (4-6 thou), paper thickness (3-10 thou), PCB copper (1.4 thou), human hair (3 thou), wire diameter, gasket thickness, and machining tolerances.

Inches to Thou (in to thou) Converter

1 in = 1,000 thou

1 Inch equals 1,000 Thou (1 in = 1,000 thou). Convert Inches to Thou with formula, table, and examples.

One inch equals exactly 1,000 thou (mils). This is the defining relationship of the thou: one thousandth of an inch. The thou is used in manufacturing, engineering, and electronics for measuring thin coatings, wire diameters, and PCB trace widths where inches are too coarse.

How to Convert Inches to Thou

thou = in × 1,000

Multiply the value in Inches by 1,000

Take your value in Inches
Multiply by 1,000
Read the result in Thou

Common Inches to Thou Conversions

Inches (in)	Thou (thou)	Status
0.001 in	1 thou
0.01 in	10 thou
0.05 in	50 thou
0.1 in	100 thou
0.25 in	250 thou
0.5 in	500 thou
1 in	1,000 thou
2 in	2,000 thou
5 in	5,000 thou
10 in	10,000 thou
12 in	12,000 thou
36 in	36,000 thou
72 in	72,000 thou
100 in	100,000 thou

Good to Know About Inches to Thou Conversion

The thou (mil) was born from the need to measure things thinner than an inch but thicker than nothing. Its metric equivalent is roughly 25.4 micrometers. American machinists think in thou; European machinists think in hundredths of a millimeter. Same precision, different languages.

Inches to Thou: What You Need to Know

An inch is exactly 1,000 thou. A standard PCB is 62 thou (0.062 inches) thick. Paint on a car is 4-6 thou. A human hair is about 3 thou. The thou provides sub-inch precision in the imperial system, analogous to how millimeters provide sub-centimeter precision in metric.

What is a Inch? in

An imperial unit of length equal to exactly 2.54 centimeters. Commonly used in the US and UK for screen sizes, body measurements, and construction.

Imperial Us-customary screen sizes construction (US) body measurements

Learn more about Inch →

What is a Thou? thou

One thousandth of an inch (0.0254 mm). Also called a mil in the US. Used in engineering, manufacturing, and for measuring thin materials like plastic film.

Imperial engineering plastic film thickness wire gauges

Learn more about Thou →

Going the other way? Use our Thou to Inches converter.

Inches to Thou FAQ

One inch contains exactly 1,000 thou. This is the definition: 1 thou = 1/1,000 inch = 0.001 inches.
Multiply inches by 1,000 or move the decimal point three places right. For example, 0.062 inches = 62 thou.
Measuring thin things in the imperial system: paint thickness (4-6 thou), paper thickness (3-10 thou), PCB copper (1.4 thou), human hair (3 thou), wire diameter, gasket thickness, and machining tolerances.

Non-Frequently Asked Questions About Inches to Thou

Questions nobody should ask - but someone did.

Maybe. 1 thou is 25.4 micrometers - about 1/3 the width of a human hair. Trained machinists claim they can feel surface roughness differences of 10-20 thou. Below 5 thou, you need instruments. Your fingertips are good sensors, but not microscopes.