CBM Calculator (Millimeters)
Enter your box dimensions in millimeters to get the CBM (cubic meters) and cubic feet of your carton.
CBM from millimeters
Millimeters are common on engineering drawings, CAD exports and precision-cut packaging specs. They give you the finest resolution of any everyday unit, so the only trick is keeping track of the zeros: a cubic meter holds a billion cubic millimeters.
How it works
Multiply the three sides in millimeters to get cubic millimeters, then divide by 1,000,000,000 (since 1000³ = 1,000,000,000 mm³ per cubic meter):
CBM = (L × W × H in mm) ÷ 1,000,000,000
A quick mental shortcut: divide each side by 1,000 to get meters first, then multiply, it lands in the same place with fewer zeros to mistype.
Worked example
Using the page defaults, a carton 1000 × 800 × 600 mm:
- Cubic millimeters:
1000 × 800 × 600 = 480,000,000 mm³ - CBM:
480,000,000 ÷ 1,000,000,000 = 0.48 CBM - Cubic feet:
0.48 × 35.3147 = 16.951 ft³
So this carton is 0.48 CBM, the same physical box as 100 × 80 × 60 cm, just measured in finer units. Round each millimeter dimension up to the nearest whole mm and measure to the widest point of the box.
Millimeter-to-CBM reference
| Box (mm) | Cubic mm | CBM | Cubic ft |
|---|---|---|---|
| 300 × 300 × 300 | 27,000,000 | 0.027 | 0.953 |
| 600 × 400 × 400 | 96,000,000 | 0.096 | 3.390 |
| 1000 × 800 × 600 | 480,000,000 | 0.480 | 16.951 |
| 1200 × 1000 × 1000 | 1,200,000,000 | 1.200 | 42.378 |
If those nine zeros are error-prone, the CBM calculator in cm divides by a million instead, and the CBM calculator in meters skips division entirely. To understand the underlying unit and where CBM is used, see what is CBM, or use the main CBM calculator for mixed units.