g/cm³ to lb/ft³
A European steel spec says 7.85 g/cm³. The US fabricator estimating plate weight wants pounds per cubic foot: 490. The conversion factor, 62.427961, is the density of water in US units — because 1 g/cm³ is water, and water is 62.4 lb/ft³. Every material's g/cm³ value, multiplied by 62.4, becomes its lb/ft³ value.
lb/ft³ = g/cm³ × 62.427961
1 g/cm³ = 62.427961 lb/ft³ — water's density in US customary units
The factor is exact — derived from SI definitions and the 1959 yard/pound agreement.
Common g/cm³ to lb/ft³ Conversions
| g/cm³ | lb/ft³ | Material / context |
|---|---|---|
| 1 g/cm³ | 62.43 lb/ft³ | Water — the bridge unit. |
| 0.917 g/cm³ | 57.2 lb/ft³ | Ice. |
| 2.7 g/cm³ | 168.6 lb/ft³ | Aluminum. |
| 7.85 g/cm³ | 490 lb/ft³ | Carbon steel. |
| 8.96 g/cm³ | 559 lb/ft³ | Copper. |
| 13.6 g/cm³ | 849 lb/ft³ | Mercury. |
| 19.3 g/cm³ | 1,205 lb/ft³ | Gold. |
Engineering Context
Density links the mass and volume families on this site — it is their ratio. For the mass numerator, the kg to g and lbs to kg converters carry the same 1959 constants that appear here; for the volume denominator, the liters to mL and cubic feet to cubic meters pages supply the cubed lengths. The density hub collects all ten converters in this family.
More: Lb Ft3 To G Cm3 · G Cm3 To Kg M3 · Kg M3 To Lb Ft3 · Density
Related Unit Converters
Frequently Asked Questions
Why is the factor exactly 62.427961?
Because 1 g/cm³ is the density of water, and water's density in US customary units is 62.427961 lb/ft³. The number carries the 1959 pound and foot, cubed.
Do I multiply or divide for steel?
Steel is 7.85 g/cm³ in metric tables and about 490 lb/ft³ in US practice. Metric-to-US, multiply by 62.427961: 7.85 × 62.4 = 490. The 62.4 shortcut is accurate to 0.05%.
Why do US fabricators want lb/ft³?
Because plate weight is estimated as volume × density, and US shop practice works in inches and pounds. A 1-inch steel plate weighs 40.8 lb/ft² — derived from 490 ÷ 12.