Density Converter – kg/m³ to lb/ft³, g/cm³ & lb/in³ in 3 Easy Steps
Density Unit Converter
Use this density converter: type a value into any unit field to instantly convert across all mass density measurements.
Use this free density converter to switch between kilograms per cubic metre (kg/m³), grams per cubic centimetre (g/cm³), pounds per cubic foot (lb/ft³) and pounds per cubic inch (lb/in³). Type a value in any box and the other three update instantly, which makes kg/m³ to lb/ft³ conversions quick for engineering, construction, shipping and science work.
Quick answer
1 g/cm³ = 1,000 kg/m³ = 62.428 lb/ft³ = 0.036127 lb/in³. To convert kg/m³ to lb/ft³, multiply by 0.062428 (or divide by 16.0185). To convert lb/ft³ to kg/m³, multiply by 16.0185. For example, steel at 7,850 kg/m³ is 7.85 g/cm³, about 490.06 lb/ft³ and 0.2836 lb/in³.
Table of Contents
Density shows up everywhere: choosing materials, estimating the weight of concrete or steel, checking fuel and liquid loads, calculating shipping weight and solving physics homework. The catch is that metric and US customary sources use different units, and the conversion factors are not round numbers.
This density converter handles all four common units at once and shows a small reference matrix so you can sanity-check results. It runs in your browser with no sign-up.
What Is Density?
Density is mass per unit volume: ρ = m ÷ V. It tells you how heavy a material is for its size. Water has a density of about 1,000 kg/m³, or 1 g/cm³, which makes it a handy reference point; materials denser than water sink, and less dense ones float.
Density Conversion Formulas
- g/cm³ to kg/m³: multiply by 1,000
- kg/m³ to lb/ft³: multiply by 0.062428
- lb/ft³ to kg/m³: multiply by 16.0185
- lb/in³ to lb/ft³: multiply by 1,728 (12 × 12 × 12)
- g/cm³ to lb/in³: multiply by 0.036127
These factors come from the definitions 1 lb = 0.45359237 kg and 1 ft = 0.3048 m, so 1 lb/ft³ = 0.45359237 ÷ 0.3048³ = 16.0185 kg/m³.
Density of Common Materials
| Material | kg/m³ | g/cm³ | lb/ft³ |
|---|---|---|---|
| Air (sea level, 15°C) | 1.225 | 0.0012 | 0.08 |
| Gasoline (approx.) | 740 | 0.74 | 46.20 |
| Ice | 917 | 0.917 | 57.25 |
| Water | 1,000 | 1.0 | 62.43 |
| Concrete (approx.) | 2,400 | 2.4 | 149.83 |
| Aluminium | 2,700 | 2.7 | 168.56 |
| Steel | 7,850 | 7.85 | 490.06 |
| Gold | 19,300 | 19.3 | 1,204.86 |
Values for mixtures such as concrete and fuels vary with composition and temperature, so check the exact figure from your supplier for design work.
How to Use the Density Converter
Step 1: Enter a Value in Any Unit
Click the box for the unit you have and type your number. Entering 7,850 kg/m³ for steel instantly shows 7.85 g/cm³, 490.059502 lb/ft³ and 0.2835992 lb/in³.
Step 2: Convert From US Units
You can start from any field. Typing 62.4 lb/ft³, a common textbook figure for water, gives about 999.55 kg/m³ and 0.9996 g/cm³.
Step 3: Use the Reference Matrix
The matrix below the fields lists the key factors: 1 g/cm³ = 1,000 kg/m³, 1 lb/ft³ = 16.0184 kg/m³, 1 kg/m³ = 0.0624 lb/ft³ and 1 lb/in³ = 1,728 lb/ft³. Press Clear Fields to start a new conversion.
Practical Uses of Density Conversion
- Construction: estimate the weight of concrete, steel or timber for structural loads and transport.
- Shipping and logistics: work out freight weight from volume, and check density-based shipping classes.
- Manufacturing: compare material datasheets from metric and imperial suppliers.
- Fluids: convert fuel, oil and chemical densities for tank and pump calculations.
- Education: check physics and chemistry answers in any unit.
Weight From Density and Volume
Once you know the density, mass is simply density × volume. One cubic metre of steel weighs about 7,850 kg. One cubic foot of water weighs about 62.4 lb. Use the density converter first so the density and volume are in matching units before you multiply.
Working with other engineering units? Try the Volumetric Flow Rate Converter or the Gas Pressure Converter.
Frequently Asked Questions
How do I convert kg/m³ to lb/ft³?
Multiply by 0.062428. For example, 1,000 kg/m³ is about 62.43 lb/ft³.
How do I convert lb/ft³ to kg/m³?
Multiply by 16.0185. For example, 150 lb/ft³ is about 2,403 kg/m³.
What is the density of water in different units?
About 1,000 kg/m³, 1 g/cm³, 62.43 lb/ft³ or 0.0361 lb/in³ at around 4°C.
Is g/cm³ the same as g/mL?
Yes. One cubic centimetre equals one millilitre, so 1 g/cm³ = 1 g/mL = 1 kg/L.
Why does density change with temperature?
Most materials expand when heated, so the same mass takes up more volume and density falls. Gases change the most.
Is my data saved?
No. The density converter runs entirely in your browser.