Density Converter
Convert density values between kg per cubic metre, g per ml, g per litre, pounds per cubic foot, and more. Useful for lab and shipping.
Enter the Details
Result will appear here...
What this converter does
Density answers a simple question, how much mass is packed into a given space, and different fields answer it in different units, from grams per cubic centimetre in the lab to pounds per cubic foot on a worksite. This converter moves a value between them, with water as the natural point of reference.
How to use it
- Type your density value into the value box.
- Set From to the unit you have, and To to the unit you want.
- Press Calculate.
The result reads back in plain words, like "1 g/cm³ is equal to 1000 kg/m³." Use Swap to flip the two units, and Reset to clear.
How it works
Every unit is referred to the kilogram per cubic metre. Because density is mass over volume, each factor is really a mass conversion divided by a volume one, but the tool works that out for you. Your value is converted to the base unit and then to the target, with results rounded to nine significant figures.
Common density conversions
The ones that come up most:
| Conversion | Value |
|---|---|
| 1 g/cm³ | 1,000 kg/m³ |
| 1 g/cm³ | 1 g/mL = 1 kg/L |
| 1 kg/m³ | 1 g/L |
| 1 lb/ft³ | about 16.02 kg/m³ |
| Water | 1,000 kg/m³ (about 62.4 lb/ft³) |
| 1 t/m³ | 1,000 kg/m³ |
Water as the reference: what floats and what sinks
There is one density worth memorising, because everything else makes sense next to it: water. Pure water is usually taken as about 1,000 kilograms per cubic metre (its peak, near 4 °C), which is the same as 1 gram per cubic centimetre, 1 gram per millilitre, or 1 kilogram per litre. The numbers line up so neatly because the metric system was built around water in the first place.
That turns density into a quick float-or-sink test. As a rule of thumb, something less dense than water tends to float and something denser tends to sink. Ice is about 0.92 g/cm³, so it floats. Cooking oil is around 0.92 too, which is why it sits on top of water. Iron is about 7.9 g/cm³ and gold about 19.3, so they drop straight to the bottom. Comparing a material to water this way is so common it has a name, specific gravity, which is just the density divided by water's.
In US engineering the same idea appears in pounds per cubic foot, where water comes out at about 62.4. And because density is mass divided by volume, every unit here pairs a weight unit with a volume unit, which is why the names look compound, like kilograms per cubic metre or pounds per gallon.
Questions people ask
What is the density of water?
About 1,000 kilograms per cubic metre, which is the same as 1 gram per cubic centimetre, 1 gram per millilitre, or 1 kilogram per litre. In US units it is roughly 62.4 pounds per cubic foot.
How do I tell if something floats?
Compare its density to water. If it is less than about 1 gram per cubic centimetre, it tends to float; if it is more, it tends to sink. That is why ice and oil float while metals sink.
How do I convert g/cm³ to kg/m³?
Multiply by 1,000. One gram per cubic centimetre is 1,000 kilograms per cubic metre, so a metal at 7.9 g/cm³ is 7,900 kg/m³.
What is specific gravity?
It is a material's density divided by the density of water. Water is 1, so anything above 1 sinks and anything below 1 floats. It is a quick way to compare materials without carrying units around.
Is a gram per millilitre the same as a gram per cubic centimetre?
Yes, exactly, because a millilitre and a cubic centimetre are the same volume. So 1 g/mL equals 1 g/cm³.
References
- National Institute of Standards and Technology (NIST), Office of Weights and Measures. The International System of Units (SI) and derived units. https://www.nist.gov/pml/owm/metric-si/si-units
Okan Atalay is a results driven senior operations manager and a graduate of Industrial Engineering from Bilkent University. With over 22 years of experience in textile manufacturing and integrated operations, he has led large scale business process improvements and strategic planning initiatives. Currently, he serves as a top mathematics expert for a global ed tech platform, where he applies his analytical expertise to solve complex mathematical problems. At Eon Tools, he reviews converter and maths tools.