Convert Gallons per Minute to Liters per Minute

Formula

L/min = GPM × 3.785411784

Derivation from SI units:

• 1 GPM = 231 in³ ÷ 60 s = 0.003785411784 m³ ÷ 60 s = 6.30901964 × 10⁻⁵ m³/s
• 1 L/min = 10⁻³ m³ ÷ 60 s
• 1 GPM = 0.0000630901964 m³/s ÷ 0.00001666666666667 m³/s per L/min = 3.785411784 L/min

Both units are defined exactly, so the factor is exact. Gallon per Minute definition: US gallon per minute; Liter per Minute definition: liter per minute.

Worked examples

1. A shower head limited to 2.5 GPM delivers 9.46352946 L/min.
   2.5 GPM × 3.785411784 = 9.46352946 L/min
2. A 10 GPM pump delivers 37.85411784 L/min.
   10 GPM × 3.785411784 = 37.85411784 L/min

Where it's used

Pump, plumbing and irrigation flows in GPM are converted to L/min for metric specifications and imported equipment.

Gallon per Minute to other flow rate units

Frequently asked questions

Sources

• Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "gallon [U.S.] per minute (gpm)".
• The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Table 8 (litre, minute).

Last reviewed: 2026-10-15. Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.