An estimate of the potential difficulty of fire containment as it relates to the flamelength at the head of the fire. A relative number related to the contribution that fire behavior makes to the amount or effort needed to contain a fire in a specified fuel type. Doubling the burning index indicates that twice the effort will be required to contain a fire in that fuel type as was previously required, providing all other parameters are held constant.

An estimate of the potential difficulty of fire containment as it relates to the flame length at the most rapidly spreading portion of a fire's perimeter.

relative measure of fire-control difficulty; doubling the index means twice the effort may be needed to control the fire (e.g., wind shift, heavier fuel load, etc).