Washington’s Department of Labor and Industries has created a worksheet based upon the NIOSH Lifting Equation to determine if a lift operation exceeds the recommended limits. A copy of this worksheet can be found here:
Worksheet: Ergonomics Calculations (40.8 KiB, 992 hits). If you are unfamiliar with the NIOSH Lifting Equation, a good resource is the Revised NIOSH Lifting Equation Document.
Sources: eLCOSH & NIOSH