# Convertisseur de débit volumique

> Convertissez L/min en gpm, gpm en L/min, cfm en m³/h et m³/h en L/s pour les pompes, la plomberie et la ventilation, avec les valeurs exactes du gallon américain et du pied cube.

Version interactive : https://www.calcopenly.com/fr/conversion/flow-rate-converter
Sujet : Convertisseurs d’unités

Flow rate is volume per time, and each unit here is a fixed number of cubic metres per second. The US gallon (3.785411784 L) and the cubic foot (28.316846592 L) are exact, so litres per minute, gallons per minute and cubic feet per minute convert with no rounding in the factors.

The default converts 10 L/min to 2.64 US gpm, close to the 2.5 gpm (9.46 L/min) of a standard US showerhead. Plumbers and pump buyers use L/min and gpm, fan and compressor ratings use cfm or m³/h, and river flows are reported in m³/s (cumecs).

The gallon here is the US gallon. An imperial gallon per minute is 4.54609 L/min, 20% more, so check which gallon a specification uses before converting it.

## Données

- **Valeur**: Un nombre dans l’unité de départ, ou accompagné de sa propre unité
- **De** (options : cubic metre per second (m³/s), cubic metre per hour (m³/h), litre per second (L/s), litre per minute (L/min), litre per hour (L/h), US gallon per minute (gal/min), cubic foot per minute (ft³/min))
- **Vers** (options : cubic metre per second (m³/s), cubic metre per hour (m³/h), litre per second (L/s), litre per minute (L/min), litre per hour (L/h), US gallon per minute (gal/min), cubic foot per minute (ft³/min))

## Résultats

- Valeur convertie — résultat principal
- Conversion
- Facteur de conversion
- Exactitude

## Formule

$$
\begin{gathered} x_{\text{to}} = x_{\text{from}} \times \dfrac{f_{\text{from}}}{f_{\text{to}}} \\ f = \text{one unit expressed in } \text{m³/s} \end{gathered}
$$

## Exemples détaillés

### 10 L/min in US gal/min

- Valeur: 10 L/min
- De: litre per minute (L/min)
- Vers: US gallon per minute (gal/min)
- **Valeur convertie: 2.6417205236 gal/min**
- Source de vérification : 10 L ÷ 3.785411784 L = 1250000000/473176473 (Python 3.8 fractions from the legal definitions)

### 1 m³/s in L/s

- Valeur: 1 m³/s
- De: cubic metre per second (m³/s)
- Vers: litre per second (L/s)
- **Valeur convertie: 1,000 L/s**
- Source de vérification : 1 m³ = 1000 L

### 1 cfm in L/min

- Valeur: 1 ft³/min
- De: cubic foot per minute (ft³/min)
- Vers: litre per minute (L/min)
- **Valeur convertie: 28.316846592 L/min**
- Source de vérification : 1 ft³ = 0.3048³ m³ = 28.316846592 L (NIST HB 44 App. C)

### 1 m³/h in L/s

- Valeur: 1 m³/h
- De: cubic metre per hour (m³/h)
- Vers: litre per second (L/s)
- **Valeur convertie: 0.2777777778 L/s**
- **Exactitude: Définitions exactes, décimale périodique**
- Source de vérification : 1000 L / 3600 s = 5/18

## Questions

### How do I convert L/min to gpm?

Divide by 3.785411784, or multiply by 0.264172. 10 L/min is 2.64 US gpm and 20 L/min is 5.28 gpm. To go from US gpm to L/min, multiply by 3.785, so a 2.5 gpm showerhead runs at 9.46 L/min.

### How do I convert cfm to m³/h?

Multiply by 1.69901. A cubic foot is 0.028316846592 m³ and an hour is 60 minutes, so 1 cfm = 1.69901079552 m³/h exactly. A 100 cfm bathroom fan moves 169.9 m³/h, or 47.2 L/s. To go from m³/h to cfm, multiply by 0.588578.

### What is a normal shower flow rate?

The US EPA puts standard showerheads at 2.5 gallons per minute, 9.46 L/min, and requires WaterSense-labelled ones to use no more than 2.0 gpm, 7.57 L/min. A 10-minute shower at 2.5 gpm uses 25 gallons, or 94.6 litres. Timing how long your shower takes to fill a 1-litre jug gives your own figure: 6 seconds means 10 L/min.

### How do I convert m³/h to L/s?

Divide by 3.6. A cubic metre is 1,000 litres and an hour 3,600 seconds, so 1 m³/h = 1,000/3,600 = 0.2778 L/s, a repeating decimal. A pump rated at 36 m³/h delivers exactly 10 L/s, or 600 L/min.

### Is gpm in US or imperial gallons?

In this converter, US gallons: 1 gpm = 3.785411784 L/min. Imperial gallons per minute are 4.54609 L/min, 20% larger, and appear on equipment specified in imperial units. To convert an imperial figure, multiply it by 1.20095 to get US gpm before entering it.

### Quelle est la précision de « Convertisseur de débit volumique » ?

La précision dépend de vos données et des hypothèses de la méthode. Le calcul décimal utilise 50 chiffres significatifs, mais les estimations, méthodes numériques et données sources peuvent être moins précises ; l’arrondi affiché ne supprime pas ces limites. Exemples résolus vérifiés à partir de sources indépendantes : 4. Par exemple, « 10 L/min in US gal/min » est vérifié à l’aide de 10 L ÷ 3.785411784 L = 1250000000/473176473 (Python 3.8 fractions from the legal definitions).

### D’où vient cette méthode ?

NIST SP 811 (2008), Guide for the Use of the SI, Appendix B — conversion factors; NIST Handbook 44, Appendix C — General tables of units of measurement.

## Sources

- [NIST SP 811 (2008), Guide for the Use of the SI, Appendix B — conversion factors](https://www.nist.gov/pml/special-publication-811)
- [NIST Handbook 44, Appendix C — General tables of units of measurement](https://www.nist.gov/pml/owm/nist-handbook-44-current-edition)