MM to Inches Converter (All Length Units)

1. Core Idea

1 inch = 25.4 mm exactly. To get inches divide millimeters by 25.4 (or multiply by 0.03937).

2. Formula

3. Quick Values

• 1 mm → 0.03937 in
• 5 mm → 0.19685 in
• 10 mm → 0.39370 in
• 25 mm → 0.98425 in
• 50 mm → 1.9685 in
• 100 mm → 3.9370 in

4. 3-Step Example

Convert 128 mm to inches

1. Formula: in = mm ÷ 25.4
2. Insert: 128 ÷ 25.4
3. = 5.0394 in

5. Uses

Manufacturing specs, woodworking, hardware sizes, monitor / device dimensions, 3D printing, machining.

6. Accuracy & Tips

• Approx mental: mm ÷ 25 ≈ inches (tiny high).
• For fractional inches: convert mm → in then express as nearest 1/16.
• Keep 4 decimals for general; more for machining.
• Reverse by multiplying by 25.4 exactly.

7. More Examples

8. FAQ