Flow Rate Calculator

Convert a measured water-filter flow rate between gallons and liters per minute, then estimate how long it will take to fill a bottle, pitcher, tank, or other container. This is useful for checking real-world performance and spotting a meaningful drop in flow.

Flow

Flow & Fill Time

Convert flow rate and estimate how long it takes to fill a bottle/pitcher/container.

Flow conversion
Estimated fill time
If flow drops over time, it may be due to clogging/sediment or nearing replacement.
Contaminants & removal basics →

How to measure and calculate flow rate

  1. Run the filtered-water outlet normally and collect water for a measured period.
  2. Enter the measured flow in gallons per minute or liters per minute.
  3. Enter the container volume to estimate its fill time at that flow rate.

Why actual flow can vary

Published flow ratings are measured under specified conditions. Household pressure, inlet temperature, tubing diameter, cartridge age, sediment loading, and the number of active filter stages can change the result. For a useful comparison, repeat the measurement with the same container and similar operating conditions.

A gradual decline may indicate normal cartridge loading; a sudden change can point to a closed valve, kinked line, trapped air, incorrect cartridge seating, or another restriction. See the troubleshooting guides or open the complete calculator hub for related tools.