How the density converter works
We use kg/m³ as the internal base. Every unit you enter is first converted to kg/m³, then back out to the target unit. This keeps the math consistent and matches common reference tables.
Formulas
base (kg/m³) = value × factorToKgM3[sourceUnit]
target = base (kg/m³) ÷ factorToKgM3[targetUnit]
Example: 1.2 g/cm³ → lb/ft³
1.2 g/cm³ = 1.2 × 1000 = 1200 kg/m³
lb/ft³ = 1200 ÷ 16.018463 = 74.9 lb/ft³
What about specific gravity?
Specific gravity (SG) is just “how many times as dense as water”. Since water is ≈ 1000 kg/m³, we use:
density (kg/m³) = SG × 1000
SG = density (kg/m³) ÷ 1000
FAQ
1. Do temperature and salinity matter?
Yes, especially for liquids. But for most day-to-day conversions, using the nominal densities (like 1000 kg/m³ for water) is perfectly fine.
2. Can I use this for bulk densities (soil, powders)?
Yes, just enter the measured bulk density in whatever unit you have and convert to the unit you need — the tool doesn’t assume a material.
3. Why are g/cm³ and g/mL the same?
Because 1 cm³ = 1 mL. So 1 g/cm³ = 1 g/mL.
Formula (LaTeX) + variables + units
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base (kg/m³) = value × factorToKgM3[sourceUnit] target = base (kg/m³) ÷ factorToKgM3[targetUnit] Example: 1.2 g/cm³ → lb/ft³ 1.2 g/cm³ = 1.2 × 1000 = 1200 kg/m³ lb/ft³ = 1200 ÷ 16.018463 = 74.9 lb/ft³
density (kg/m³) = SG × 1000 SG = density (kg/m³) ÷ 1000
- No variables provided in audit spec.
- NIST — Weights and measures — nist.gov · Accessed 2026-01-19
https://www.nist.gov/pml/weights-and-measures - NIST — SI units — nist.gov · Accessed 2026-01-19
https://www.nist.gov/pml/owm/metric-si/si-units
Last code update: 2026-01-19
- Initial audit spec draft generated from HTML extraction (review required).
- Verify formulas match the calculator engine and convert any text-only formulas to LaTeX.
- Confirm sources are authoritative and relevant to the calculator methodology.