Enter all task parameters. The NIOSH RLE (Waters et al. 1994) calculates the Recommended Weight Limit (RWL) by applying six multipliers to the load constant (23 kg). The Lifting Index (LI) is the actual load divided by the RWL. LI > 1.0 indicates elevated musculoskeletal risk.
Distance from ankles to hands at lift origin
Height of hands above floor at origin
Vertical travel from origin to destination
Angle of body twist from sagittal plane
NIOSH RLE results
Lifting Index (LI)
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Enter all inputs
RWL
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HM
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VM
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DM
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AM
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FM
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CM
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Recommended Weight Limit (RWL)—
Actual load weight—
Risk interpretation—
RWL multiplier breakdown
NIOSH RLE: RWL = LC × HM × VM × DM × AM × FM × CM, where LC = 23 kg. LI = L/RWL. LI ≤ 1.0: nominal risk for most healthy adults. 1.0 < LI ≤ 3.0: elevated risk; task redesign recommended. LI > 3.0: high risk; immediate intervention required. Frequency multipliers per NIOSH Table 5 (Waters et al., 1994). Equation does not apply to one-handed lifts, seated lifts, constrained postures, or hot environments. Standard: NIOSH Technical Report 94-110 (Waters et al. 1994).
Composite Lifting Index (CLI)
Add each lifting task below. The CLI accounts for the cumulative metabolic loading of multiple distinct lifting tasks performed during the same work period. Each task requires its own RWL calculated at frequency-independent (FI) and frequency-dependent (FD) conditions. Results follow the CLI procedure of Waters et al. (1994).
Composite Lifting Index
Add at least two tasks and enter all required inputs to compute the CLI.
Individual task lifting indices
CLI calculation: tasks are ranked by LI (highest first). CLI = LI₁ + Σ[LIFi(FTi) − LIFi(FTi−1)] where FT represents cumulative frequency. Each task's frequency-independent RWL is calculated using the maximum permissible frequency for its V and duration. Standard: NIOSH Technical Report 94-110, Section 4.