Specific Gravity Converter Formula

Understand the math behind the specific gravity converter. Each variable explained with a worked example.

Use the Specific Gravity Converter

Formulas Used

kg/m³

kg_per_m3 = value * 1000

g/cm³

g_per_cm3 = value

lb/ft³

lb_per_ft3 = value * 62.428

lb/gal

lb_per_gal = value * 8.345

Variables

VariableDescriptionDefault
valueSpecific Gravity(SG)1.025

How It Works

Specific Gravity

Specific Gravity = Density of Substance / Density of Water

Since water density is 1 g/cm³ (or 1000 kg/m³ at 4°C), specific gravity is numerically equal to density in g/cm³.

Quick Conversions

  • kg/m³ = SG x 1,000
  • g/cm³ = SG x 1
  • lb/ft³ = SG x 62.428
  • lb/gal = SG x 8.345

    • Worked Example

    Convert SG 1.025 (seawater).

    value = 1.025
    1. 01kg/m³ = 1.025 x 1000 = 1025
    2. 02g/cm³ = 1.025
    3. 03lb/ft³ = 1.025 x 62.428 = 63.99
    4. 04lb/gal = 1.025 x 8.345 = 8.554

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