1 g/cm³ in lb/ft³
- Value
- 1 g/cm³
- From
- gram per cubic centimetre (g/cm³)
- To
- pound per cubic foot (lb/ft³)
- Converted value
- 62.4279605761 lb/ft³
Checked against: 1000 kg/m³ ÷ (0.45359237 kg / 0.028316846592 m³) = 14158423296/226796185
Density converter
Convert g/cm³ to kg/m³, kg/m³ to lb/ft³ and lb/gal (ppg), and g/mL to kg/L, with exact factors from the 1959 pound and foot.
By AdminDrafted with AI writing toolsUpdated Checked examples: 4
Converted value
lb/ft³
Converted value: 62.4279605761 lb/ft³
- Conversion
- 1 g/cm³ ≈ 62.42796 lb/ft³
- Conversion factor
- 62.4279605761
- Exactness
- Exact definitions, repeating decimal
1 g/cm³ is about 62.42796 lb/ft³.
The same amount counted in each unit
1 g/cm³ in every Density unit
| Unit | Value | Definition |
|---|---|---|
| kilogram per cubic metre (kg/m³) | 1,000 | Base unit |
| gram per cubic centimetre (g/cm³) | 1 | 1 g/cm³ = 1,000 kg/m³, exact |
| gram per millilitre (g/mL) | 1 | 1 g/mL = 1,000 kg/m³, exact |
| kilogram per litre (kg/L) | 1 | 1 kg/L = 1,000 kg/m³, exact |
| pound per cubic foot (lb/ft³) | 62.42796 | 1 lb/ft³ = 0.45359237/0.028316846592 kg/m³, exact |
| pound per cubic inch (lb/in³) | 0.03612729 | 1 lb/in³ = 0.45359237/0.000016387064 kg/m³, exact |
| pound per US gallon (lb/gal) | 8.345404 | 1 lb/gal = 0.45359237/0.003785411784 kg/m³, exact |
How it's calculated S
Convert gram per cubic centimetre to kilogram per cubic metre
1 g/cm³ = 1,000 kg/m³, exact
Convert kilogram per cubic metre to pound per cubic foot
1 lb/ft³ = 0.45359237/0.028316846592 kg/m³, exact
Combined factor
Both units are defined exactly, but the converted value is a repeating decimal; it is shown to 12 significant figures.
About the density converter
Density is mass per volume, so each unit is a mass unit divided by a volume unit, held here as kilograms per cubic metre. The metric units differ by powers of 1,000 (1 g/cm³ = 1 g/mL = 1 kg/L = 1,000 kg/m³), and the imperial ones follow from the exact pound and foot: 1 lb/ft³ ≈ 16.0185 kg/m³.
The default converts 1 g/cm³, close to the density of water, to 62.428 lb/ft³. Engineers use lb/ft³ (pcf) for soils and concrete, drillers use lb/gal (ppg) for drilling mud, and materials data sheets use g/cm³.
Density changes with temperature, and the converter only changes units. Pure water is densest near 4 °C at about 999.97 kg/m³ and is about 998.2 kg/m³ at 20 °C, so, for these stated temperature examples at ordinary pressure, “1 g/cm³ for water” is an approximation within 0.2%.
What is the formula for density?
Some displayed converted decimals below are rounded; defined factors are separate from display precision.
Density is mass divided by volume: ρ = m/V. A sample with a mass of 100 g and a volume of 20 cm³ has a density of 100 ÷ 20 = 5 g/cm³, which is 5000 kg/m³. The same equation rearranges to m = ρV to find mass and V = m/ρ to find volume.
Using the density equation
Each version of the equation answers a different question:
- Density from a sample. Weigh it and measure its volume, then divide: 100 g in 20 cm³ is 5 g/cm³.
- Mass from volume, m = ρV. Two liters of a liquid with a density of 0.80 kg/L weigh 0.80 × 2 = 1.6 kg.
- Volume from mass, V = m/ρ. A kilogram of aluminum, at 2.70 g/cm³, takes up 1,000 ÷ 2.70 = 370 cm³.
Match the units before dividing: grams with cm³ or mL, kilograms with liters or m³. Then the answer comes out in a standard density unit with no extra factor.
Converting density units
Grams per cubic centimeter, grams per milliliter and kilograms per liter are the same size, because 1 mL = 1 cm³ and 1 kg/L = 1,000 g/1,000 mL. Each equals 1,000 kg/m³, so steel at 7.85 g/cm³ is 7,850 kg/m³.
The pound-based units use the exact 1959 pound and foot. One lb/ft³ is 16.0185 kg/m³, so concrete at 150 lb/ft³ is about 2,400 kg/m³. The lb/gal unit, called ppg for drilling mud, uses the US gallon.
| Density unit | kg/m³ per unit |
|---|---|
| kg/m³ | 1 |
| g/cm³ | 1000 |
| g/mL | 1000 |
| kg/L | 1000 |
| lb/ft³ | ≈ 16.0184633740 |
| lb/in³ | ≈ 27679.9047102 |
| lb/US gal | ≈ 119.826427317 |
The ≈ rows are exact definitions whose decimals repeat, shown to 12 significant figures. The BIPM SI Brochure gives kg/m³ as the SI unit, and NIST's mass-per-volume table lists the other factors.
Water, temperature and specific gravity
At ordinary pressure, pure water is densest near 4 °C at about 999.97 kg/m³ and falls to about 998.2 kg/m³ at 20 °C, so treating it as 1 g/cm³ is right to within 0.2%. A measured density holds at the temperature it was measured at, whatever unit it is written in.
Specific gravity is a material's density divided by the density of water, so it has no unit. Against water at 4 °C it equals the density in g/cm³ almost exactly: a liquid of 0.80 g/cm³ has a specific gravity of about 0.80.
Mistakes with density
- Mixing kilograms with cubic centimeters. 0.1 kg ÷ 20 cm³ is 0.005 kg/cm³, which is 5000 kg/m³, not 0.005 kg/m³. A kg/cm³ is a million times a kg/m³.
- Confusing lb/ft³ with lb/in³. A cubic foot holds 1,728 cubic inches, so the same number means a density 1,728 times higher in lb/in³.
- Using weight per volume. Specific weight, in N/m³ or lbf/ft³, is density multiplied by gravity, a different quantity from the mass densities here.
To convert the mass or the volume on its own, use the weight converter or the volume converter. The cooking converter applies ingredient densities to turn cups of flour or sugar into grams.
Worked examples
1000 kg/m³ in g/mL
- Value
- 1000 kg/m³
- From
- kilogram per cubic metre (kg/m³)
- To
- gram per millilitre (g/mL)
- Converted value
- 1 g/mL
Checked against: 1000 kg/m³ = 1 g/cm³ = 1 g/mL
1 lb/gal in kg/m³
- Value
- 1 lb/gal
- From
- pound per US gallon (lb/gal)
- To
- kilogram per cubic metre (kg/m³)
- Converted value
- 119.826427317 kg/m³
Checked against: 0.45359237 / 0.003785411784
1 lb/in³ in g/cm³
- Value
- 1 lb/in³
- From
- pound per cubic inch (lb/in³)
- To
- gram per cubic centimetre (g/cm³)
- Converted value
- 27.6799047102 g/cm³
Checked against: 0.45359237 kg / 0.000016387064 m³ ÷ 1000
Questions
How do I convert g/cm³ to kg/m³?
Multiply by 1,000. A cubic metre holds 10⁶ cubic centimetres and a kilogram is 1,000 grams, so 1 g/cm³ = 1,000 kg/m³. Aluminium at 2.70 g/cm³ is 2,700 kg/m³, and steel at about 7.85 g/cm³ is 7,850 kg/m³. g/mL and kg/L are the same size as g/cm³.
What is specific gravity?
The ratio of a substance's density to the density of water, so it has no unit. Referenced to water at 4 °C (999.97 kg/m³), specific gravity equals the density in g/cm³ with a difference of about 0.003%: a liquid of 0.80 g/cm³ has a specific gravity of about 0.80. Other references, such as water at 60 °F, can change later significant digits.
How do I convert lb/ft³ to kg/m³?
Multiply by 16.0185. A pound is 0.45359237 kg and a cubic foot 0.028316846592 m³, both exact, so 1 lb/ft³ ≈ 16.01846337 kg/m³. Normal-weight concrete at about 150 lb/ft³ is about 2,400 kg/m³, and 1,000 kg/m³ is 62.43 lb/ft³.
What does ppg mean for drilling mud?
Pounds per US gallon, the density unit of oilfield drilling fluids. 1 lb/gal is 119.826 kg/m³, so fresh water at 20 °C is 8.33 ppg and a 12 ppg mud is 1,438 kg/m³, or 1.44 g/cm³. Mud weight sets the pressure the fluid column exerts at the bottom of the well.
Is the density of water exactly 1 g/cm³?
No, but close. At ordinary pressure, pure water peaks at about 999.97 kg/m³ near 4 °C and is about 998.2 kg/m³ at 20 °C. The early gram concept in 1795 was based on the mass of 1 cm³ of water. From 1901 to 1964, the litre was defined from the volume of 1 kg of water at maximum density and standard pressure. This history explains the numerical closeness; actual water density still depends on temperature.
About this calculator
Sources
Checked against references
This calculator includes 4 worked examples with independently sourced answers. They run in the test suite, and you can run them here too.