A fuel sub-metering mechanism for appliances that consume fuel. Each appliance may have a firing rate indicator. An individual fuel line may be connected to each appliance. A main fuel line may be connected to individual fuel lines. A meter may be connected to the main fuel line. A processor may be connected to the firing rate indicators and to the meter. The meter may measure total fuel consumption by the appliances. The processor may provide a sub-meter estimate of fuel consumed by each appliance. The sub-meter estimate may be based at least in part on a firing rate of the respective appliance and the total fuel consumption as indicated by the meter.