Density Converter

What is density?

Density is how much mass is packed into a given volume - mass divided by volume. Its SI unit is the kilogram per cubic meter (kg/m³), but chemistry and everyday work more often use the gram per cubic centimeter (g/cm³), which is exactly 1,000 times larger: 1 g/cm³ = 1000 kg/m³. Water is the handy reference point - it has a density of about 1000 kg/m³, or 1 g/cm³. Anything denser than water sinks in it; anything less dense floats.

How to convert density units

Every density conversion goes through the coherent SI derived unit, the kilogram per cubic meter: each unit carries a fixed factor for how many kg/m³ it represents, and you convert by multiplying by the source factor and dividing by the target. Because a liter is a cubic decimeter, the metric liter-based units line up cleanly - 1 g/L = 1 kg/m³ and 1 kg/L = 1000 kg/m³. The US and Imperial units follow from fixed definitions of the pound, ounce and gallon: 1 lb/ft³ = 16.018463 kg/m³ and 1 lb/in³ = 27,679.905 kg/m³.

Worked example

Take water at 1000 kg/m³. Dividing by 1,000 gives 1 g/cm³, the value chemists usually quote. Converting to US units, 1000 ÷ 16.018463 = 62.428 lb/ft³ - the figure used in plumbing and HVAC work. Steel, by contrast, is about 7850 kg/m³ (≈ 7.85 g/cm³ or 490 lb/ft³), which is why a solid steel block sinks, while a steel hull floats only because it's hollow.

When you'll use a density converter

Density conversion comes up across engineering, science and trade: comparing material densities quoted in g/cm³ against handbooks in lb/ft³, sizing tanks and shipping loads, working out buoyancy and whether something floats, reading concentration limits given in mg/L or µg/L, and checking the specific gravity of fuels, oils and brines. The table above lists your value in all 42 supported units at once - across SI units, the full liter-based metric ladder, and the US and Imperial units like lb/ft³ and slug/ft³ - so you can read off the equivalent you need without converting twice.

Frequently asked questions

How many kg/m³ are in one g/cm³?

One gram per cubic centimeter equals exactly 1,000 kilograms per cubic meter, because a cubic centimeter is one millionth of a cubic meter while a gram is one thousandth of a kilogram. To go the other way, divide kg/m³ by 1,000 to get g/cm³.

What is the formula to convert lb/ft³ to kg/m³?

Multiply the pound per cubic foot value by 16.018463374 to get kilograms per cubic meter. For example, 50 lb/ft³ becomes about 800.9 kg/m³.

Is lb/in³ a larger unit than lb/ft³?

Yes, the pound per cubic inch is much larger. One lb/in³ equals exactly 1,728 lb/ft³, because there are 1,728 cubic inches in one cubic foot, so the same density reads as a far smaller number in lb/in³.

What is a slug per cubic foot?

The slug per cubic foot is the coherent density unit in the US gravitational system, where the slug is the mass that one pound-force accelerates at one foot per second squared. One slug/ft³ equals about 515.38 kg/m³, roughly half the density of water.

How do I convert g/cm³ to lb/ft³?

Multiply the gram per cubic centimeter value by 62.4279606 to get pounds per cubic foot. So water at 1 g/cm³ is about 62.43 lb/ft³.

Are kg/L and g/cm³ the same value?

Yes, they are numerically identical. One kilogram per liter equals one gram per cubic centimeter, since a liter holds 1,000 cm³ and a kilogram is 1,000 grams, so both equal 1,000 kg/m³.