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Calculation Machine

CFM to L/s Calculator

Convert CFM to litres per second.

Reviewed by the Calculation Machine team · How we check our maths

Your values

ⓘ Live results

Results
Airflow
70.79 L/s
In m³/h
254.9
In m³/s
0.0708
In CFM
150

Working

  1. 1150 CFM x 0.471947 = 70.79 L/s

Quick answer

One CFM equals 0.471947 litres per second.

The formula

L/s = CFM x 0.471947

Worked example

Worked example

Using the values the calculator loads with.

Inputs

  • Airflow150 CFM

Result

  • Airflow70.79 L/s
  • In m³/h254.9
  • In m³/s0.0708
  • In CFM150

How to use the CFM to L/s Calculator

  1. 1Enter the CFM rating you want to convert.
  2. 2Read litres per second for code compliance checks.
  3. 3Use m³/h when sizing metric ducting.

Frequently asked questions

Why is L/s used in codes?

It scales neatly for per-person and per-square-metre ventilation rates.

What is a typical bathroom rate?

Many codes ask for 15 L/s intermittent, about 32 CFM, or 8 L/s continuous.

About this calculator