French Measurements
Metric, Mètres, Kilos, Litres
Updated May 2026
France invented the metric system in 1795 (décret du 18 germinal an III) and has used it exclusively for all official measurements ever since. The Système international d’unités (SI), maintained by the BIPM based in Sèvres just outside Paris, is the modern descendant of the original revolutionary metric system. French speech and French writing use only metric units; imperial units (feet, inches, pounds, gallons) are essentially never used in France for any commercial, scientific, official, or everyday purpose.
This page covers the standard metric units in French (mètre, centimètre, kilogramme, litre, hectare, tonne), the typographic conventions for writing them (number + non-breaking space + symbol), the decimal-with-virgule rule for fractional measurements, and the everyday phrasing for height, weight, temperature, and cooking quantities.
Why France Uses Only the Metric System
The metric system was created during the French Revolution as a deliberate replacement for the chaotic patchwork of regional measurement units that pre-revolutionary France had inherited from medieval and Renaissance practice. Different provinces, different cities, even different trades within the same city used different definitions of livre (pound), pied (foot), aune (ell), boisseau (bushel). The decree of 18 germinal an III (7 April 1795) established the metre, the gramme, the litre, and the are as decimal-based units derived from natural physical references (the metre as 1/10,000,000 of the quarter-meridian from pole to equator).
By 1840, the metric system was the only legal system in France for commerce and administration. Other European countries adopted it through the 19th and early 20th centuries. The Bureau international des poids et mesures (BIPM) was founded in 1875 by the Convention du Mètre treaty, signed in Paris by 17 countries, to maintain the international metric standards. The BIPM headquarters at Sèvres just outside Paris remains the global authority for SI definitions today.
For French learners coming from imperial-system countries (UK, US, Liberia, Myanmar are essentially the only non-fully-metric countries left), this means you need to internalise metric units rather than translate. A French speaker giving directions says cinq cents mètres (500 m), not “a third of a mile”. A French chef writes 250 g de farine, not “1 cup of flour”. A French weather report announces vingt-cinq degrés, not “77 degrees Fahrenheit”. Quick mental conversion thresholds: 1 m ≈ 3.28 ft, 1 kg ≈ 2.2 lb, 1 L ≈ 0.26 US gal, 1 km ≈ 0.62 mi, °C × 1.8 + 32 = °F.
Reference Table
| Value | French | English equivalent | Note |
|---|---|---|---|
| 1 m | un mètre | 1 metre (~3.28 ft) | Base SI unit. |
| 1,75 m | un mètre soixante-quinze | 1.75 m (~5'9") | Common adult height. |
| 100 m | cent mètres | 100 m (~328 ft) | Track and field reference. |
| 1 km | un kilomètre | 1 km (~0.62 mi) | Standard road distance unit. |
| 10 km | dix kilomètres | 10 km (~6.2 mi) | Standard race distance. |
| 1 cm | un centimètre | 1 cm (~0.39 in) | Hundredth of a metre. |
| 1 mm | un millimètre | 1 mm (~0.039 in) | Thousandth of a metre. |
| 1 g | un gramme | 1 g (~0.035 oz) | Thousandth of a kg. |
| 1 kg | un kilogramme (un kilo) | 1 kg (~2.2 lb) | Standard weight unit. |
| 1 t | une tonne | 1 metric tonne (1000 kg, ~2205 lb) | Cargo and freight. |
| 1 L | un litre | 1 L (~0.26 US gal) | Standard volume unit. |
| 75 cl | soixante-quinze centilitres | 750 ml (~25 fl oz) | Standard wine bottle. |
| 1 ha | un hectare | 1 ha (10 000 m², ~2.47 acres) | Land area. |
| 20 °C | vingt degrés | 20°C (~68°F) | Mild room temperature. |
Height, Weight, and the Implicit Centimes Pattern
Personal heights in French follow a pattern very similar to the implicit-centimes form for prices. J’ai un mètre soixante-quinze (I am 1.75 m / about 5’9”) is the standard form. The first number is in metres; the second number, after no preposition, is implicitly understood as centimètres because the structure makes it unambiguous. Adult heights typically range un mètre cinquante (1.50 m, short) to un mètre quatre-vingt-quinze (1.95 m, very tall), and the form stays consistent throughout that range.
For weight, the unit is kilo (the everyday-speech short form of kilogramme). Je pèse soixante-quinze kilos (I weigh 75 kg). For babies, the implicit-grammes pattern appears: il pèse trois kilos deux cents (he weighs 3.2 kg, with the second number implicitly grammes). For larger objects (luggage, freight, food in bulk), kilogrammes is used in formal speech, kilos in casual speech.
Distances follow no particular implicit-unit shortening. Road distances are in kilomètres with the full unit named: cent kilomètres (100 km), cinq cents kilomètres (500 km), mille kilomètres (1000 km). For walking distances under a kilometre, mètres: cinq cents mètres (500 m), deux cents mètres (200 m). The shift point from metres to kilometres in everyday speech is around 700-800 m, where most speakers would say “un kilomètre” if rounding up or “huit cents mètres” if being precise.
Temperature: Always Celsius
All temperatures in France are Celsius (degrés Celsius, °C). Body temperature normal: trente-sept degrés (37°C). Fever threshold: trente-huit degrés (38°C). Room temperature: vingt à vingt-deux degrés. Summer hot day: trente degrés (30°C, hot). Winter cold day: cinq degrés (5°C). Freezing: zéro degré. Below zero: moins cinq degrés (-5°C, “minus five”).
For weather forecasts, la température is invariably given in Celsius. Il fera vingt-cinq degrés à Paris means “it will be 25°C in Paris”. The plural form degrés is used for any value other than one (degré). The construction il fait + temperature is the standard way to state the current temperature.
For oven temperatures in cooking, French recipes specify in degrees Celsius and often also as thermostat (Th) numbers, which correspond to a heat scale used by older French ovens (Th 1 = 30°C, Th 6 = 180°C, Th 7 = 210°C, Th 8 = 240°C). The thermostat numbering is roughly °C / 30, but it is not an exact division. Modern recipes typically give just the °C value: cuire à cent quatre-vingts degrés.
Common Measurement Phrases
| French | English |
|---|---|
| Je mesure un mètre soixante-quinze | I am 1.75 m tall |
| Je pèse soixante-douze kilos | I weigh 72 kg |
| Le bébé pèse trois kilos deux | The baby weighs 3.2 kg |
| Il fait vingt-cinq degrés | It is 25°C |
| Roulez à cent trente sur autoroute | Drive at 130 km/h on the motorway |
| C'est à cinq cents mètres | It is 500 m away |
| Une bouteille de soixante-quinze centilitres | A 75 cl bottle |
| Cinq hectares de terrain | 5 hectares of land |
| Un sac de dix kilos de pommes de terre | A 10 kg sack of potatoes |
| Cuire à cent quatre-vingts degrés | Cook at 180°C |
Frequently Asked Questions
What measurement system does France use?
The metric system, exclusively. France was the country that invented the metric system: the Décret du 18 germinal an III (7 April 1795) established the first decimal metric units. By 1840 the metric system was the only legal measurement standard in France. Since 1960 France has used the modern Système international d'unités (SI), the same standard adopted internationally by the BIPM. Imperial units (feet, inches, pounds, gallons) are not used in any official, commercial, or scientific French context.
How do you say a height in French?
Use mètres with the virgule decimal: un mètre soixante-quinze (1,75 m) is "one metre seventy-five" or 1.75 m. Personal heights are typically given in this format: J'ai un mètre soixante-douze (1.72 m). Children and very short heights may use centimètres alone: il fait quatre-vingt-dix centimètres (90 cm). Tall heights stay in metres: deux mètres dix (2.10 m).
How do you write metric units in French?
Number, then non-breaking space, then the unit symbol. Examples: 100 m, 1,75 m, 50 km, 2,5 kg, 0,75 L. The unit symbol is invariable (no plural-s on m, kg, L, km). The full unit name does take a plural-s in writing: cent mètres, deux kilogrammes, but the abbreviated symbol stays singular even in plural contexts. Source: BIPM SI brochure, sections 5.4 and 5.5.
What is the French word for kilogram, kilometre, etc.?
Kilogramme (often shortened to kilo in everyday speech), kilomètre, centimètre, millimètre, hectomètre (100 m, rarely used outside athletics), décamètre, décimètre. Litre, centilitre (100 cl in a litre, common for wine bottles), décilitre, millilitre. Hectare for area (10 000 m²). Tonne for 1000 kg (in France: tonne, sometimes "tonne métrique" for clarity).
How do you say temperature in French?
In degrés Celsius (°C). The pattern: il fait vingt degrés (it is 20°C), il fait moins cinq (it is -5°C, "minus five"), il fait zéro (it is freezing, 0°C). For body temperature: trente-sept degrés (37°C, normal). For oven temperature: cuire à cent quatre-vingts degrés (cook at 180°C). The symbol °C is written with a non-breaking space: 20 °C. Fahrenheit is not used in France.
How do you express a person's weight in French?
In kilogrammes (kilos in everyday speech). Je pèse soixante-dix kilos (I weigh 70 kg). The verb is "peser". For approximation: je fais dans les soixante-dix kilos (I weigh around 70 kg). For babies: trois kilos deux cents (3.2 kg, with the implicit "grammes" after the second number, like the implicit centimes pattern for prices).
How do you say cooking measurements in French?
Most French recipes use grammes (g), centilitres (cl) for liquids, and cuillères for spoons (cuillère à café = teaspoon, ~5 ml; cuillère à soupe = tablespoon, ~15 ml). Common quantities: 250 g (deux cent cinquante grammes) of flour, 500 g of meat, 25 cl (vingt-cinq centilitres) of milk, 75 cl for a standard wine bottle. Recipe portions are typically given as "pour 4 personnes" (for 4 people).