Inches to Millimeters Converter
Convert between inches and millimeters for precision measurements
Precision Length Calculator
Imperial unit (1 inch = 25.4 mm)
Metric unit (25.4 mm = 1 inch)
Conversion Results
Conversion Formula: Millimeters = Inches × 25.4
Calculation: 0" × 25.4 = 0.0 mm
Reference: This is an exact conversion - 1 inch = exactly 25.4 millimeters
Common Conversions
| Inches | Millimeters | Usage |
|---|---|---|
| 0.01 | 0.254 | Fine thread |
| 0.1 | 2.54 | Wire gauge |
| 0.25 | 6.35 | Small screw |
| 0.5 | 12.7 | Coin thickness |
| 1 | 25.4 | Thumb width |
| 2 | 50.8 | Credit card |
| 3 | 76.2 | Business card |
| 4 | 101.6 | Phone width |
| 6 | 152.4 | Phone length |
| 8 | 203.2 | Tablet width |
| 10 | 254 | Small ruler |
| 12 | 304.8 | 1 foot |
Quick Reference
Basic Conversions
1 inch = 25.4 mm (exact)
1 mm = 0.0393701 inches
1 cm = 10 mm
1 foot = 304.8 mm
Precision Work
Machining tolerances
Engineering drawings
Quality control
Usage Tips
Manufacturing specs
Tool measurements
Material thickness
Precision Measurement Examples
Bolt Thread
0.1" = 2.54 mm pitch
Sheet Metal
0.5" = 12.7 mm thickness
Machine Part
2.5" = 63.5 mm diameter
Hardware
0.25" = 6.35 mm bolt
Understanding Inches and Millimeters Conversion
What are Inches and Millimeters?
Inches are part of the Imperial system, while millimeters are part of the metric system. Millimeters are commonly used for precision work, manufacturing, and engineering because they provide finer measurement granularity. The exact conversion is 1 inch = 25.4 millimeters.
When to Use Each Unit
Use Inches For:
- • General measurements in the US
- • Construction and carpentry
- • Screen sizes and displays
- • Plumbing and pipe sizes
Use Millimeters For:
- • Precision manufacturing
- • Engineering specifications
- • Machining tolerances
- • Scientific measurements
Conversion Formula
Millimeters = Inches × 25.4
Inches = Millimeters ÷ 25.4
Practical Examples
Machining Example
0.5" drill bit = 0.5 × 25.4 = 12.7 mm
Phone Screen Example
6" phone = 6 × 25.4 = 152.4 mm diagonal
Bolt Size Example
1/4" bolt = 0.25 × 25.4 = 6.35 mm diameter
Detailed Conversion Table
Inches to Millimeters (Precise Values)
| Inches | Millimeters | Context |
|---|---|---|
| 1/32" | 0.794 | Fine adjustment |
| 1/16" | 1.588 | Small drill bit |
| 1/8" | 3.175 | Common drill |
| 1/4" | 6.35 | Small bolt |
| 1/2" | 12.7 | Medium bolt |
| 3/4" | 19.05 | Large bolt |
Millimeters to Inches (Common Values)
| Millimeters | Inches | Context |
|---|---|---|
| 1 mm | 0.0394" | Fine measurement |
| 5 mm | 0.197" | Small component |
| 10 mm | 0.394" | 1 centimeter |
| 25 mm | 0.984" | ~1 inch |
| 50 mm | 1.969" | ~2 inches |
| 100 mm | 3.937" | ~4 inches |