The formula
ft³ = m³ × 35.31466672
Where the factor comes from — each unit by its definition, then its size in SI:
1 m³ is the SI unit of volume.1 ft³ = ft³ = 0.028316846592 m³
Dividing the two SI sizes gives the factor: 35.3146667215 (rounded for display; the underlying ratio is fixed by the definitions). The reverse factor is 0.028316846592.
The cubic metre is the SI unit of volume; the litre is exactly one thousandth of it. The US and UK gallons are different sizes, which is why a fuel-economy figure in mpg depends on which country printed it.
Worked examples
- A soft-drink bottle (2 L): 0.002 m³ = 0.0706293 ft³ — 0.002 × 35.31466672 = 0.0706293
- A paint bucket (5 US gal): 0.0189271 m³ = 0.668403 ft³ — 0.0189271 × 35.31466672 = 0.668403
- A water tank: 1 m³ = 35.3147 ft³ — 1 × 35.31466672 = 35.3147
- A drinks can (330 mL): 0.00033 m³ = 0.0116538 ft³ — 0.00033 × 35.31466672 = 0.0116538
Frequently asked questions
How many cubic feet is 1 m³?
1 m³ = 35.3146667215 ft³.
How do I convert cubic feet back to cubic metres?
Divide by 35.3146667215 — or multiply by 0.028316846592: 1 ft³ = 0.028316846592 m³.