Eng Unit Converter

Density is mass per unit volume, a fundamental property linking mass and volumetric measurements. The SI unit is kg/m³, but g/cm³ (= kg/L) is widely used in laboratory and material specifications. Key conversions: 1 g/cm³ = 1,000 kg/m³ = 1 kg/L = 62.428 lb/ft³, 1 lb/ft³ = 16.0185 kg/m³. Reference values: water = 1,000 kg/m³ at 4°C, air = 1.225 kg/m³ at sea level and 15°C, steel ≈ 7,850 kg/m³, aluminum ≈ 2,700 kg/m³. Density is used in buoyancy calculations, fluid mechanics (Reynolds number), material selection, weight estimation of structures, and quality control (verifying alloy composition). Process engineers use density to convert between mass and volumetric flow rates. Common pitfalls: forgetting the ×1,000 factor between g/cm³ and kg/m³, confusing density with specific gravity (SG is dimensionless), assuming fluid density is constant (it varies with temperature and pressure, especially for gases), and confusing specific gravity with specific weight (force per unit volume, N/m³).