Grams per Liter to Grams per cm³ Density Converter
Common Conversions
| g/L | g/cm³ |
|---|---|
| 0.1 | 0.0001 |
| 0.5 | 0.0005 |
| 1 | 0.001 |
| 2 | 0.002 |
| 5 | 0.005 |
| 10 | 0.01 |
| 25 | 0.025 |
| 50 | 0.05 |
| 100 | 0.1 |
| 1000 | 1 |
Why this conversion matters in chemistry
Gas densities and dilute aqueous concentrations live naturally in g/L because the values come out manageable — air at 1.29 g/L, CO₂ at 1.98 g/L, normal serum albumin at 35–50 g/L. Converting to g/cm³ shifts the same number down by a factor of 1000, putting it on the scale chemistry density tables use. The conversion shows up most when comparing a gas-phase density to a liquid-phase reference, or reconciling a clinical-chemistry concentration in g/L with a benchtop density measurement in g/cm³.
Formula
Where the factor comes from
Two definitions with quite different pedigrees meet in this ratio. The cubic centimeter is purely geometric — a cube of side 10⁻² m — and since 1983 the meter has been fixed by assigning an exact value to the speed of light, so cm³ inherits that exactness without any vessel ever being involved. The liter arrives from the other direction. It is not an SI unit at all, only a name tolerated alongside SI, and it is set equal to one cubic decimeter. A decimeter is ten centimetres, so a cubic decimeter holds 10³ = 1000 cubic centimetres. Dividing g/L by 1000 therefore rests on cubing a factor of ten and nothing else. The numerator is untouched and the denominator rescaled, so the result is exact whatever happens to be in the flask.
Precision and significant figures
The thousand is definitional, so figures pass through unchanged — but they stop looking like figures. 1.293 g/L becomes 0.001293 g/cm³, where the three leading zeros are placeholders and the value still carries four significant digits. Writing 1.293 × 10⁻³ g/cm³ removes the ambiguity and is worth the extra keystrokes. What limits you depends on where the g/L came from. A gas density obtained through PV = nRT inherits whatever the pressure and temperature readings carried, so three figures is often generous. A solute concentration in g/L is bounded by the balance and the glassware, and a Class A volumetric flask is specified to something on the order of a tenth of a percent.
Worked Examples
The density of water at 4 °C — the conversion's calibration anchor.
The density of dry air at old STP (0 °C, 1 atm) — the reference for any gas-density comparison.
The density of CO₂ at the same STP conditions — heavier than air, which is why it pools in low spots.
Common mistakes
A gas density without its temperature and pressure
Air is 1.293 g/L at 0 °C and 1 atm but about 1.204 g/L at 20 °C — a seven percent spread across ordinary room conditions. Dividing by 1000 preserves that ambiguity perfectly. A gas density in either unit is a statement about a state, and quoting it without the state it belongs to leaves the number unusable.
22.4 L/mol used outside its conditions
The molar-volume route to a gas density holds only at the conditions the molar volume was computed for. 22.414 L/mol belongs to 0 °C and 1 atm; the 0 °C and 1 bar convention gives 22.711 L/mol, and 25 °C at 1 atm gives about 24.47 L/mol. Choosing the wrong one biases the density by one to nine percent before any unit conversion begins.
The liter in g/L is the finished volume
A g/L concentration means solute mass per liter of finished solution, not per liter of solvent. Dissolving 60 g of a salt and topping up to the mark is not the same operation as adding it to a liter already measured out, and for concentrated solutions the two differ by several percent. Converting to g/cm³ cannot repair a solution made up on the wrong basis.