A kilogram is a unit of mass and a liter is a unit of volume, so there is no direct rate of conversion. If you know the density of a substance, you can make the conversion from kilograms to liters for that substance.
Find the density of a substance
Look up the density of the substance you are attempting to convert for online or in a reference book. If it is a pure element, its density can be found on any periodic table. Density is normally listed in grams per cubic centimeter.
Find the mass of the substance
Weigh your item to determine its mass in kilograms.
Convert to like units of measure
At this point, you need to convert the units of measure in order to be able to work with the numbers. If the density is supplied in grams per cubic centimeter, the conversion is unnecessary; there are 1,000 grams in a kilogram, and 1,000 cubic centimeters in a liter, so the two conversion factors cancel each other out.
Divide the mass by the density
In order to determine the volume of the substance in liters, divide the mass (as measured in kilograms) by the density (as measured in grams per cubic centimeter).