What does deciliter mean?
A deciliter is a metric unit of volume equal to one tenth of a litre, or 100 millilitres. It belongs to the family of prefixed units built on the litre, alongside the centiliter and the milliliter, and its name derives from the Latin 'decimus', meaning tenth. Although rarely spoken aloud in daily conversation, the deciliter appears regularly in medical and scientific contexts — most familiarly in blood test results, where glucose and cholesterol concentrations are often expressed as milligrams per deciliter. In many European countries it also serves as a practical kitchen measure, roughly comparable to half a cup, making it common in recipes from Scandinavia and continental Europe. British English typically spells the word 'decilitre', while American English favours 'deciliter'. Abbreviated as dL or dl, it offers a convenient mid-scale unit: large enough to be useful for measuring liquids in cooking and clinical work, yet small enough to express quantities precisely without resorting to awkward fractions of a litre.
nounA metric unit of volume equal to one tenth of a litre (100 millilitres).
- A metric unit of volume equal to one tenth of a litre (100 millilitres).
"The recipe calls for two deciliters of milk."
"The lab reported her blood glucose level as 95 milligrams per deciliter."
"Add half a deciliter of olive oil to the dressing and whisk well."
Regular plural; the British spelling forms the plural 'decilitres'. In technical writing the abbreviated form dL often stands for both singular and plural.
"He measured out three deciliters of flour."
Blood sugar readings in mg/dL are actually measuring milligrams per deciliter — so a unit most people have never heard of quietly appears on millions of lab reports every day.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of deciliter
The word 'deciliter' was formed in the wake of the French Revolution's metric reforms at the end of the eighteenth century, when the litre was established as a base unit of volume and standard prefixes were adopted to mark its multiples and divisions. It combines the Latin prefix 'deci-', meaning 'tenth' (from 'decimus'), with 'litre', which itself traces back through French to the Greek 'litra', an ancient unit of weight. Cognate forms appear across the metric-using languages of Europe, including the French 'décilitre' and German 'Deziliter', all sharing the same Latin root seen in words like 'decimal' and 'decimate'.
Related word forms
How deciliter is actually used
The spelling 'decilitre' is standard in British English, while 'deciliter' predominates in American English. The abbreviation 'dL' or 'dl' is common in scientific and medical contexts. The unit is more frequently encountered in European countries that use the metric system for cooking and everyday measurement than in the United States, where it appears mainly in medical reporting such as blood test results.
Easily confused with deciliter
A deciliter is one tenth of a litre, whereas a litre is the full base unit of volume.
A centiliter is one hundredth of a litre (10 millilitres), ten times smaller than a deciliter.