Liters per Minute (L/min) Calculator

Calculate volumetric flow rate instantly with unit conversions and bucket test helper

Enter the volume of fluid
Enter the time period

🪣 Bucket Test Helper

Measure real flow by timing how long it takes to fill a bucket

00:00.0

How It Works

This calculator determines volumetric flow rate in liters per minute using two methods:

Volume & Time Method:
Flow (L/min) = Volume (L) / Time (min)

Convert your volume to liters and time to minutes, then divide.

Area & Velocity Method:
Flow (L/min) = Area (m²) × Velocity (m/s) × 60000

The factor 60000 converts from m³/s to L/min (1 m³ = 1000 L, 1 min = 60 s).

Real-World Examples

🚿 Shower Flow

A bucket fills 10 liters in 50 seconds → 12 L/min

10 L ÷ (50/60 min) = 12 L/min

🌱 Garden Hose

15 liters fill in 90 seconds → 10 L/min

15 L ÷ (90/60 min) = 10 L/min

🔧 Pipe Flow

5cm diameter pipe at 1 m/s velocity → 117.8 L/min

π × (0.025 m)² × 1 m/s × 60000 = 117.8 L/min

How to Measure Flow (Bucket Test)

  1. Get a bucket of known capacity (e.g., 10 liters)
  2. Place bucket under the tap or hose
  3. Start the timer as water begins to flow
  4. Stop the timer when bucket is full
  5. Calculate: Flow = Bucket size / Time in minutes

Frequently Asked Questions

What is L/min?
Liters per minute (L/min) is a unit measuring volumetric flow rate – how much volume of fluid passes through a point per unit time. It’s commonly used for water flow in taps, hoses, pumps, and plumbing systems.
How do I convert L/min to GPM?
To convert liters per minute to US gallons per minute (GPM), multiply by 0.264172. For imperial gallons, multiply by 0.219969. Our calculator shows both conversions automatically.
How can I measure flow rate at home?
The easiest method is the bucket test: fill a container of known volume (like a 10L bucket) and time how long it takes. Divide the volume by the time to get your flow rate. Use our bucket test helper tool above for automatic calculation.
What’s a typical household tap flow rate?
Kitchen taps typically flow at 6-12 L/min, bathroom taps at 4-8 L/min, showers at 8-15 L/min, and garden hoses at 10-20 L/min. Modern water-saving fixtures may have lower flow rates.
Why use the area and velocity method?
When you know the pipe diameter and fluid velocity (from a flow meter or calculation), you can determine flow rate without measuring volume directly. This is useful for engineering applications and system design.