L⁻¹
per liter
Number densityCost per volumeexact by definition
The per litre is exactly 10³ m⁻³. Particle counting in liquids uses it: total particle counts in ultrapure water, plankton counts in a net tow and coliform densities are all per litre.
| 1 L⁻¹ (Number density) | 1,000 m⁻³ |
| 1 $/L (Cost per volume) | 1,000 $/m³ |
As a unit of cost per volume
Cost per litre is the retail-scale volumetric price, used for fuel at the pump in metric countries, for beverages and for laboratory and treatment chemicals. It is exactly one thousandth of the corresponding price per cubic metre, since a cubic metre holds exactly one thousand litres. The conversion is exact by definition of the litre.
Solvers that use number density