Fuel Flow from AFR Calculator

Working backward from air flow to fuel flow

Air flow is often the easier quantity to measure directly using an anemometer or duct flow meter on the combustion air supply - this calculator lets you infer or cross-check fuel flow against a target air-fuel ratio without measuring fuel flow directly.

Worked example

For 1,000 kg/hr of air flow at a 14.7 air-fuel ratio:

Fuel Flow = 1000 / 14.7 = 68.0272 kg/hr fuel flow

This calculation is especially useful for quick field verification - if measured fuel flow differs meaningfully from this calculated value, it can indicate a combustion tuning issue, sensor drift, or a genuine deviation from the intended air-fuel ratio worth investigating further.