1 mm to Inches
Convert 1 millimeters to inches — instant, accurate, and easy
The Answer
Browse digital calipers on Amazon.
📄 Free printable mm to inches chart (PDF) — every mm from 1 to 300.
How to Convert 1 mm to Inches
To convert 1 millimeters to inches, divide the millimeter value by 25.4. This is because one inch equals exactly 25.4 millimeters — a standard defined by international agreement.
The Calculation
Applying the formula to 1 mm:
Result Summary for 1 mm
- Decimal inches: 0.0394″
- Fractional inches: 3/64″ (nearest 1/64)
- Feet and inches: 0 ft 0.04 in
Reference Table — Values Near 1 mm
| Millimeters | Decimal Inches | Fractional Inches |
|---|---|---|
| 1 mm | 0.0394″ | 3/64″ |
| 2 mm | 0.0787″ | 5/64″ |
| 3 mm | 0.1181″ | 1/8″ |
| 4 mm | 0.1575″ | 5/32″ |
1 mm in Other Units
Millimeters convert cleanly into every other length unit. Here is 1 mm expressed seven different ways — useful when a drawing, spec sheet or supplier quotes a unit other than inches.
| Unit | 1 mm equals |
|---|---|
| Centimeters (cm) | 0.1 cm |
| Meters (m) | 0.001 m |
| Inches (in) | 0.0394 in |
| Feet (ft) | 0.0033 ft |
| Yards (yd) | 0.00109 yd |
| Thousandths of an inch (mil) | 39.4 mil |
| Typographic points (1/72 in) | 2.83 pt |
How Accurate Is Each Fraction of 1 mm?
1 mm equals 0.0394″ (rounded to four decimal places). Any fraction is a further rounding of the full-precision value, so each one carries a small error. This table shows the closest fraction at each common denominator and how far it actually sits from 1 mm.
| Rounded to | Fraction | Decimal | Fraction vs. original |
|---|---|---|---|
| Nearest 1/2″ | 0″ | 0.0000″ | −1.000 mm (below original) |
| Nearest 1/4″ | 0″ | 0.0000″ | −1.000 mm (below original) |
| Nearest 1/8″ | 0″ | 0.0000″ | −1.000 mm (below original) |
| Nearest 1/16″ | 1/16″ | 0.0625″ | +0.588 mm (above original) |
| Nearest 1/32″ | 1/32″ | 0.0313″ | −0.206 mm (below original) |
| Nearest 1/64″ | 3/64″ | 0.0469″ | +0.191 mm (above original) |
For woodworking, DIY and general workshop use, 3/64″ is the practical choice — it lands within 0.4 mm of 1 mm. For machining, toolmaking or CAD, use the decimal value 0.0394″ rather than any fraction.
FAQ About 1 mm to Inches
How many inches is 1 mm?
1 millimeters equals 0.0394 inches (rounded to 4 decimal places), or approximately 3/64″ (nearest 1/64 inch).
How accurate is the 1 mm to inches conversion?
The conversion of 1 mm to 0.0394 inches uses the exact definition 1 inch = 25.4 millimeters; the four-decimal result is rounded, so it is approximate.
Can I convert 1 mm to feet?
Yes. 1 millimeters equals approximately 0 ft 0.04 in.
📏 Need to measure 1mm accurately?
Digital calipers typically display readings to 0.01 mm resolution, enough to check 1 mm (≈ 0.0394″). See current options:
→ See digital calipers on Amazon
Read our digital calipers buying guide →
As an Amazon Associate, we earn from qualifying purchases at no extra cost to you.