40 cm = 400 mm. To convert centimeters to millimeters, multiply by 10: 40 × 10 = 400.
How to convert centimeters to millimeters
mm = cm × 10
- 1 cm = 10 mm (and 1 mm = 0.1 cm).
- Multiply the amount by the factor: 40 × 10 = 400.
- Answer: 40 cm = 400 mm.
Centimeters to Millimeters table
| Centimeters (cm) | Millimeters (mm) |
|---|---|
| 35 cm | 350 mm |
| 36 cm | 360 mm |
| 37 cm | 370 mm |
| 38 cm | 380 mm |
| 39 cm | 390 mm |
| 40 cm | 400 mm |
| 41 cm | 410 mm |
| 42 cm | 420 mm |
| 43 cm | 430 mm |
| 44 cm | 440 mm |
| 45 cm | 450 mm |
| cm | mm |
|---|---|
| 1 cm | 10 mm |
| 5 cm | 50 mm |
| 10 cm | 100 mm |
| 50 cm | 500 mm |
| 100 cm | 1,000 mm |
| 1,000 cm | 10,000 mm |
Good to know
1 inch = 2.54 cm exactly; 1 cm = 10 mm; 1 m = 100 cm; 1 foot = 12 inches = 30.48 cm.