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 for single or multiple lifting tasks. The Lifting Index (LI) is an index of the relative physical stress for performing a single lifting task and the Composite Lifting Index (CLI) is an index of the overall physical stress for performing multiple lifting tasks. NIOSH recommends an LI and a CLI of 1 or less for protecting workers from physical stress related to development of low back musculoskeletal 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.