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🏋️ NIOSH lifting equation calculator (RNLE)

Compute the Recommended Weight Limit (RWL) and Lifting Index (LI) with the full Revised NIOSH Lifting Equation — at origin and destination — and the Composite Lifting Index (CLI) for multi-task jobs. Uses the official NIOSH frequency-multiplier table, finds the limiting factor and exports to Word & Excel.

Step 1 — Task setup
Step 2 — The six task variables (metric)

H — Horizontal distance (cm)

Horizontal distance from the mid-point between the ankles to the hands. HM = 25/H (HM = 1 if H ≤ 25; task not recommended if H > 63).

Origin
Destination

V — Vertical location (cm)

Height of the hands above the floor at the start/end of the lift. VM = 1 − (0.003 × |V − 75|).

Origin
Destination

D — Travel distance (cm)

Vertical travel = |Vdest − Vorigin| (auto). DM = 0.82 + (4.5/D); DM = 1.0 if D < 25 (min D = 25).

D = 40 cm

A — Asymmetry angle (°)

Twist angle of the body from the sagittal (straight-ahead) plane. AM = 1 − (0.0032 × A).

Origin
Destination

F — Frequency (lifts/min)

Average lifts per minute. FM comes from the official NIOSH table (duration band above + vertical location V).

C — Coupling

Quality of the hand-to-object grip. CM = Good 1.00, Fair 0.95 (1.00 if V ≥ 75), Poor 0.90.

⚖️ Actual load (kg)

The weight actually lifted. LI = load ÷ RWL (lower of origin/destination RWL).

Step 4 — Composite Lifting Index (CLI)

Add each sub-task with its own 6 variables, frequency and load. The CLI ranks sub-tasks by decreasing single-task LI and sums the FM-difference increments (NIOSH method). The shared duration band below sets every sub-task's FM.

ℹ️ This calculator implements the Revised NIOSH Lifting Equation (Waters, Putz-Anderson, Garg & Fine, 1994). It is valid for two-handed, smooth lifts under ideal conditions for healthy adults — it does not cover one-handed lifts, carrying, pushing/pulling, extreme heat/cold, unstable loads or constrained postures, and is not a substitute for assessment by a qualified ergonomist. Where a value is indicative, verify it by direct observation and measurement of the actual task.