What does decilitre mean?
A decilitre is a metric unit of volume equal to one tenth of a litre, or 100 millilitres. It sits between the more familiar litre and millilitre on the metric scale and is abbreviated as dl or dL. Although less commonly used in everyday speech than litres or millilitres, the decilitre appears regularly in European cookery books, where liquid ingredients are often measured in decilitres, and in medical and laboratory settings — most famously in blood-alcohol readings expressed as grams per decilitre, and in blood glucose values reported in milligrams per decilitre. The word combines the Latin prefix deci-, meaning 'tenth', with 'litre', the base metric unit of capacity. British English spells it 'decilitre', while American English prefers 'deciliter'. For readers accustomed to cups and fluid ounces, one decilitre corresponds to roughly 3.4 fluid ounces or a little under half a cup, making it a handy bridge between metric and imperial measures.
nounA metric unit of volume equal to one tenth of a litre, or 100 millilitres.
- A metric unit of capacity equal to one tenth of a litre (100 ml), used especially in cooking, medicine, and laboratory measurement.
"The recipe calls for two decilitres of milk."
"Add three decilitres of water to the flour."
"The patient's blood alcohol level was measured at 0.5 grams per decilitre."
Standard plural; 'deciliters' in American spelling.
"The bottle holds five decilitres."
Doctors often report blood glucose in milligrams per decilitre — a unit you've probably read without ever saying aloud.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of decilitre
The word decilitre derives from French décilitre, formed from the Latin prefix deci- ('tenth') combined with litre, the fundamental metric unit of capacity adopted during the French Revolution's standardization of weights and measures in the late eighteenth century. It entered English alongside other decimal subdivisions of the litre such as the centilitre and millilitre as the metric system spread internationally in the nineteenth century. Cognate forms exist across European languages, including German Deziliter and Spanish decilitro.
Related word forms
How decilitre is actually used
The spelling 'decilitre' follows British conventions, while American English typically uses 'deciliter'. The abbreviation is dl or dL. It is more common in European contexts, recipes, and clinical measurements than in everyday American usage.
Easily confused with decilitre
A decilitre is one tenth of a litre (100 ml), whereas a centilitre is one hundredth of a litre (10 ml).