Flow Rate Converters

Flow rate is volume divided by time — the number that decides whether a pump works, a pipe is big enough, or an HVAC system moves enough air. The units split along the same two axes as the volume and time families behind them: the metric world flows in liters per minute and cubic meters per hour, the American world in gallons per minute and cubic feet per minute. Every factor on this page is exact — the US gallon is 231 in³ by definition, the foot is 0.3048 m by the 1959 agreement, and the liter is a cubic decimeter. None of the constants here is rounded, and all of them chain back to the same anchors the rest of the site uses.

Liters per Minute & Gallons per Minute — Pumps & Fixtures

L/min to GPM 1 L/min = 0.2642 GPM. A kitchen faucet at 8 L/min is 2.1 GPM. Every European pump spec meets an American one through this factor. × 0.26417 GPM to L/min 1 GPM = 3.7854 L/min. A 5 GPM shower head flows 18.9 L/min. The exact reciprocal of the US gallon. × 3.7854

Liters per Minute & Cubic Meters per Hour — Municipal & Industrial

L/min to m³/h 1 L/min = 0.06 m³/h. A 100 L/min booster pump delivers 6 m³/h. The ×0.06 factor is pure decimal — 60 minutes in an hour, 1,000 L in a cubic meter. × 0.06 m³/h to L/min 1 m³/h = 16.667 L/min. A 12 m³/h circulation pump flows 200 L/min. The reverse of the same decimal chain. × 16.667

Gallons per Minute & Cubic Meters per Hour — Crossing the Atlantic

GPM to m³/h 1 GPM = 0.2271 m³/h. A 60 GPM fire pump moves 13.6 m³/h. The US gallon chained through the liter to the cubic meter. × 0.22712 m³/h to GPM 1 m³/h = 4.4029 GPM. A 10 m³/h irrigation pump is 44 GPM. The reciprocal transatlantic flow. × 4.4029

Liters per Second & Liters per Minute — Fire & High Flow

L/s to L/min 1 L/s = 60 L/min. A 4 L/s fire hydrant flows 240 L/min. The ×60 rule is exact — seconds to minutes. × 60 L/min to L/s 1 L/min = 0.0167 L/s. A 30 L/min lab pump is 0.5 L/s. The reverse of the same definition. ÷ 60

Gallons per Minute & Cubic Feet per Minute — HVAC & Air

GPM to CFM 1 GPM = 0.1337 CFM. The 231 in³ gallon over the 1,728 in³ cubic foot. Chiller and cooling-tower water vs air comparisons. × 0.13368 CFM to GPM 1 CFM = 7.4805 GPM. The exact reciprocal — a cubic foot holds 7.48 US gallons. × 7.4805

What's on this page

Ten converters covering the five flow units that actually show up in engineering work — liters per minute (SI process), gallons per minute (US pumps and fixtures), cubic meters per hour (municipal and industrial), liters per second (fire and high-flow), and cubic feet per minute (HVAC and compressed air). Flow rate is a derived quantity: volume ÷ time. That means every factor here is the product of a volume constant from the volume pages and the 60-second minute from the time family. The GPM↔CFM pair is the only one that carries a non-decimal constant (0.1336805556), because it divides the 231 in³ gallon by the 1,728 in³ cubic foot. If you're converting mass flow — kilograms per hour, pounds per minute — that's density × volume flow, and the density hub has the mass side. Flow rate tells you how much moves; density tells you what it weighs.