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Liters to KG Converter

Enter a volume in liters and choose the substance to get its weight in kilograms, grams and pounds. Pick water, milk, oils, fuels, honey or concrete, or type your own density in kg/L.

Last updated: October 24, 2026

Volume

Substance

Custom density

kg/L

kg/L is the same number as g/mL or g/cm³

Enter your values to see the result.

How to use the Liters to KG Converter

Enter the volume in liters.
Choose the substance, or pick Custom density and type its kg/L value.
Read the mass in kilograms, plus grams and pounds.
Use the reverse factor to see how many liters make 1 kg.
Compare substances in the table or download it as CSV.

Liters to kilograms formula

Liters measure volume and kilograms measure mass, so the link between them is the substance's density in kilograms per liter:

kg = liters × density (kg/L)

Water is the easy case: 1 liter weighs almost exactly 1 kg, which is how the metric system was originally defined. Lighter liquids weigh less per liter: 50 L of gasoline at 0.745 kg/L is 50 × 0.745 = 37.3 kg. Heavier ones weigh more: a 1 L jar of honey holds about 1.42 kg. To reverse the conversion, divide: liters = kg ÷ density.

How much does 1 liter weigh?

Substance	Density (kg/L)	1 L (kg)	5 L (kg)	20 L (kg)	1 L (lb)
Water	1	1	5	20	2.2
Seawater	1.025	1.025	5.12	20.5	2.26
Milk (whole)	1.03	1.03	5.15	20.6	2.27
Olive oil	0.91	0.91	4.55	18.2	2.01
Vegetable oil	0.92	0.92	4.6	18.4	2.03
Gasoline (petrol)	0.745	0.745	3.73	14.9	1.64
Diesel fuel	0.84	0.84	4.2	16.8	1.85
Ethanol (alcohol)	0.789	0.789	3.95	15.8	1.74
Motor oil	0.88	0.88	4.4	17.6	1.94
Antifreeze (ethylene glycol)	1.113	1.113	5.56	22.3	2.45
Maple syrup	1.33	1.33	6.65	26.6	2.93
Honey	1.42	1.42	7.1	28.4	3.13
Concrete (fresh, normal weight)	2.4	2.4	12	48	5.29

Typical values near room temperature. Density in kg/L is the same number as g/mL and g/cm³; multiply by 1,000 for kg/m³.

Tips for accurate results

Temperature changes density. Warm liquids expand. Water is 1.000 kg/L at 4 °C, 0.998 kg/L at 20 °C and about 0.958 kg/L near boiling, so a liter of hot water weighs about 40 g less.
Fuel varies by season and blend. Gasoline ranges from about 0.71 to 0.77 kg/L and diesel from about 0.82 to 0.86 kg/L. Use the custom field with the value from your supplier's data sheet when it matters.
Weight limits and shipping. Converting liters to kg is the quickest way to check payload, shelf or luggage limits for liquids; don't forget the container's own weight.
Concrete and other mixes are sold by volume but loaded by weight: 1 cubic meter (1,000 L) of normal concrete weighs about 2,400 kg.

Frequently asked questions

How do you convert liters to kg?

Multiply the volume in liters by the density in kg/L. For water (about 1 kg/L), 1 liter is 1 kg; for olive oil (0.91 kg/L), 1 liter is 0.91 kg.

Is 1 liter always 1 kg?

Only for water, and only approximately (1.000 kg at 4 °C, 0.998 kg at 20 °C). Other substances have different densities, so a liter of gasoline is about 0.75 kg and a liter of honey about 1.42 kg.

How much does 1 liter of diesel weigh?

About 0.84 kg (typically 0.82 to 0.86 kg depending on blend and temperature), so 50 liters of diesel weighs roughly 42 kg.

How much does 1 liter of milk weigh?

Whole milk is about 1.03 kg per liter, slightly heavier than water because of dissolved proteins, sugar and minerals.

How do I convert kg back to liters?

Divide the mass by the density: liters = kg ÷ kg/L. For example, 10 kg of olive oil is 10 ÷ 0.91 = 10.99 liters.

Is kg/L the same as g/mL?

Yes. 1 kg/L = 1 g/mL = 1 g/cm³ = 1,000 kg/m³, so you can enter a density from any of these units as the same number (divide kg/m³ by 1,000).

Are all the tools on FreeToolCabin tested for quality and accuracy?

Yes! Every tool on our site undergoes automated Q/A testing in real browser environments to ensure high precision, correct output, and zero errors. If you happen to spot a bug or have a suggestion, please contact us at [email protected] and our team will review it right away.

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