Grams per cubic centimetre to pounds per cubic inch (g/cm³ to lb/in³)

The formula

lb/in³ = g/cm³ × 0.036127292

Where the factor comes from — each unit by its definition, then its size in SI:

• 1 g/cm³ = g / cm³ = 1,000 kg/m³
• 1 lb/in³ = lb / in³ = 27,679.9047102 kg/m³

Dividing the two SI sizes gives the factor: 0.0361272920001 (rounded for display; the underlying ratio is fixed by the definitions). The reverse factor is 27.6799047102.

Density is mass per volume. 1 g/cm³ is exactly 1000 kg/m³ — water is close to that — and the buoyancy and pressure formulas take kg/m³.

Worked examples

• Water at room temperature (approximately): 1 g/cm³ = 0.0361273 lb/in³ — 1 × 0.036127292 = 0.0361273
• Typical structural steel (7850 kg/m³): 7.85 g/cm³ = 0.283599 lb/in³ — 7.85 × 0.036127292 = 0.283599
• Air at sea level (ISA) (1.225 kg/m³): 0.001225 g/cm³ = 4.42559 × 10⁻⁵ lb/in³ — 0.001225 × 0.036127292 = 4.42559 × 10⁻⁵

Frequently asked questions