684 mm = 68.4 cm. To convert millimeters to centimeters, divide by 10: 684 ÷ 10 = 68.4.
How to convert millimeters to centimeters
cm = mm × 0.1
- 1 mm = 0.1 cm (and 1 cm = 10 mm).
- Multiply the amount by the factor: 684 × 0.1 = 68.4.
- Answer: 684 mm = 68.4 cm.
Shortcut: dividing by 10 gives the same result as multiplying by 0.1.
Millimeters to Centimeters table
| Millimeters (mm) | Centimeters (cm) |
|---|---|
| 679 mm | 67.9 cm |
| 680 mm | 68 cm |
| 681 mm | 68.1 cm |
| 682 mm | 68.2 cm |
| 683 mm | 68.3 cm |
| 684 mm | 68.4 cm |
| 685 mm | 68.5 cm |
| 686 mm | 68.6 cm |
| 687 mm | 68.7 cm |
| 688 mm | 68.8 cm |
| 689 mm | 68.9 cm |
| mm | cm |
|---|---|
| 1 mm | 0.1 cm |
| 5 mm | 0.5 cm |
| 10 mm | 1 cm |
| 50 mm | 5 cm |
| 100 mm | 10 cm |
| 1,000 mm | 100 cm |
Good to know
1 inch = 2.54 cm exactly; 1 cm = 10 mm; 1 m = 100 cm; 1 foot = 12 inches = 30.48 cm.