Millimeters ↔ Inches Converter
Convert between millimeters and inches instantly
📚 Millimeters ↔ Inches Conversion Details
Millimeters to Inches Formula
To convert millimeters to inches, divide the millimeters by 25.4.
Inches to Millimeters Formula
To convert inches to millimeters, multiply the inches by 25.4.
Bidirectional Conversion
This converter works both ways simultaneously:
- Type in millimeters → inches updates automatically
- Type in inches → millimeters updates automatically
- No buttons to click - works as you type
Common Uses
- Engineering drawings
- Machining and manufacturing
- Jewelry and small measurements
- Electronics components
- 3D printing dimensions
📏 How This Converter Works
This is a bidirectional converter that works in real-time:
- Millimeters → Inches: When you type in the millimeters field, the inches field automatically updates
- Inches → Millimeters: When you type in the inches field, the millimeters field automatically updates
- No swapping needed: Both conversions happen simultaneously
- Real-time: Updates happen as you type, no button clicks required
inches = millimeters ÷ 25.4
millimeters = inches × 25.4
// Example 1: Type "100" in millimeters
inches = 100 ÷ 25.4 = 3.9370
// Example 2: Type "1" in inches
millimeters = 1 × 25.4 = 25.4
📊 Conversion Table
| Millimeters | Inches | Fraction (Approx) |
|---|---|---|
| 1 mm | 0.03937" | 1/25" |
| 5 mm | 0.19685" | 3/16" |
| 10 mm | 0.3937" | 25/64" |
| 25 mm | 0.98425" | 63/64" |
| 50 mm | 1.9685" | 1 31/32" |
| 100 mm | 3.9370" | 3 15/16" |
📏 Millimeters to Inches Fraction Chart
| Millimeters | Inches Decimal | Inches Fraction |
|---|---|---|
| 0.5 mm | 0.0197" | 1/64" |
| 1 mm | 0.0394" | 1/32" |
| 2 mm | 0.0787" | 5/64" |
| 3 mm | 0.1181" | 1/8" |
| 4 mm | 0.1575" | 5/32" |
| 5 mm | 0.1969" | 3/16" |
| 6 mm | 0.2362" | 15/64" |
| 7 mm | 0.2756" | 9/32" |
| 8 mm | 0.3150" | 5/16" |
| 9 mm | 0.3543" | 23/64" |
| 10 mm | 0.3937" | 25/64" |
❓ Frequently Asked Questions
A: There are exactly 25.4 millimeters in one inch.
A: Both input fields work simultaneously. When you change the millimeters value, inches updates automatically. When you change the inches value, millimeters updates automatically.
A: The conversion factor is exactly 25.4. 1 inch = 25.4 millimeters, and 1 millimeter = 1/25.4 = 0.0393701 inches.
A: Yes, the conversion uses the exact factor of 25.4. This converter provides results up to 4 decimal places for precision.
A: Millimeters are commonly used in engineering, manufacturing, and countries using the metric system. Inches are commonly used in construction, carpentry, and countries using the imperial system.