GPM (gallons/min) Calculator - Calculator Academy

Reviewed By: Patrick Myers (BSME)

Calculate the gallons per minute (GPM) from the bucket text, fill time, or from another flow unit.

GPM Calculator

Measure flow rate from a bucket test, estimate fill or drain time, or convert between common flow units.

Bucket Test

Fill / Drain Time

Flow Converter

Enter the amount of water collected and how long it took to fill. This is the most practical way to estimate faucet, hose, pump, or well flow rate.

Collected Volume

Volume Unit

Fill Time

Time Unit

Enter the tank or container size and a known flow rate. Use this to estimate how long it will take to fill or empty a system.

Estimate Type

Tank or Container Volume

Volume Unit

Known Flow Rate

Flow Unit

Convert a known flow value to another unit, then see equivalent GPM, gallons per hour, gallons per day, and example fill times.

Flow Value

From Unit

To Unit

Converted Value

The following formula is used to calculate gallons per minute.

GPM = 60 / X

To calculate gallons per minute, simply divide 60 by the number of seconds it takes to fill one gallon.

GPM is defined as the rate of flow of water in gallons per minute.

How to calculate GPM?

First, gather a 1 gallon bucket.
Place the gallon bucket under the water flow.
Next, measure the time it takes to fill.
Using a stop watch, measure the time it takes to fill the bucket.
Finally, calculate GPM.
Calculate the GPM using the formula above and the seconds from step 2.

What is GPM?

GPM stands for gallons per minute and is a measure of the volumetric flow rate of a liquid, most often water.