Flow Rate Calculator: convert flow rate instantly. Full formula, unit table, and worked example.
Flow rate describes how much fluid passes a point during a stated time. In practical work it appears on water meters, pump curves, fuel systems, irrigation equipment, laboratory apparatus, and utility bills. The key distinction on this page is volumetric flow: the result measures volume per time, not mass per time and not the speed of the fluid at one point. The flow rate page keeps the quantity and its dimensions visible so a reader can audit the calculator result.
The relevant units here are litres per minute (L/min), litres per second (L/s), cubic metres per hour (m³/h), cubic metres per second (m³/s), and US gallons per minute (US gal/min). Unit symbols are part of the meaning: a value per metre, per second, or per litre cannot be safely read as a plain number. Convert the complete quantity before inserting it into another equation, and keep temperature, density, pressure, reaction, or interface conditions beside the result when they affect the property.
The symbol Q is volumetric flow, V is volume, and t is elapsed time. The conversion factors are linear because every unit represents the same volume divided by time. Flow rate is not the same as velocity: for a full pipe, Q = A·v, so the same flow can have different velocity when the cross-sectional area changes. The unit conversion calculator can provide a broader comparison, while the molarity calculator is useful when a concentration problem needs moles, mass, or dilution rather than equivalents.
These pages are designed for transparent estimates and study. A familiar-looking output can still be wrong if the input belongs to another unit family or if a domain assumption was omitted. Treat the displayed answer as a documented calculation with a stated basis, not as a measurement certificate or a substitute for a specification.
Q = V ÷ t; 1 L/s = 60 L/min = 3.6 m³/h = 1.0000e-3 m³/s = 15.850323 US gal/min
The symbol Q is volumetric flow, V is volume, and t is elapsed time. The conversion factors are linear because every unit represents the same volume divided by time. Flow rate is not the same as velocity: for a full pipe, Q = A·v, so the same flow can have different velocity when the cross-sectional area changes.
Worked check: A flow of 1 L/s is 60 L/min, 3.6 m³/h, 0.001 m³/s, and 15.850323 US gal/min. A hose delivering 12 L/min therefore supplies 0.2 L/s, or 0.72 m³/h. These values describe the same delivery rate and should not be added together as separate outputs.
The displayed conversion is a rate, so the time window matters. A 10 L/min tap delivers 600 L in an hour, but pressure, valve position, elevation, pipe friction, and downstream demand may cause a real system's rate to vary. For a tank or bill, multiply Q by a measured duration only after confirming that the rate was representative.
A conversion should preserve the underlying quantity: changing cP to Pa·s, L/s to m³/h, or M to N with a declared equivalent factor changes the label and numerical representation, not the sample or reaction. Reverse the calculation where possible and check the expected order of magnitude before using the result in a design, report, recipe, experiment, or comparison.
If two credible sources disagree, compare their units and conditions before averaging or choosing the more convenient value. Differences often come from temperature, density, pressure reference, interface cleanliness, concentration basis, endpoint, or rounding rather than from arithmetic. Keep the original value and source so the assumption can be revisited.
This is an educational flow-rate conversion aid. Plumbing, pump, drainage, irrigation, and pressure-system sizing should use measured conditions and qualified engineering review.