Burner Turndown Ratio Calculator

How Far a Burner Can Modulate Without Cycling Off

Turndown ratio expresses how much a burner can reduce output before it has to shut off and restart rather than continuing to modulate, a key spec for equipment serving highly variable loads.

The Formula

Worked Example

A burner with a maximum firing rate of 500 kW and a minimum stable rate of 50 kW:

How to Use This Calculator

1. Enter the burner's Maximum Firing Rate.
2. Enter its Minimum Stable Firing Rate.
3. Select Calculate to get the turndown ratio.

Related Calculations

Check current firing rate against this range in the Burner Firing Rate Calculator, or size the burner for the load in the Burner Sizing Calculator.