The NIOSH lifting equation calculator (NLE Calc) is based on the Applications Manual for the Revised NIOSH Lifting Equation (Pub No. 94-110) and can be used to calculate the recommended weight limit (RWL) and lifting index (LI) for single or multiple lifting tasks. The LI is an index of the relative physical stress for performing a particular lifting task, while the composite LI or CLI is an index of the overall physical stress for performing multiple lifting tasks. NIOSH recommends an LI and CLI of 1 or less for protecting workers from physical stress related to development of low back disorders. Please refer to the Applications Manual for the Revised NIOSH Lifting Equation publication for examples and details on how calculations are performed and what the results imply.