Define the lifted mass
Use the complete mass supported during the assessed upward lift, in kilograms.
HOISTING & TRAVEL / TOOL 16
Hoisting Power Calculator
Compare the power needed to raise the same suspended mass at different speeds before discussing a hoist drive package.
Before you start: required inputs
- Add the material, lifting attachment and rigging carried by the mechanism. Confirm the hook-block convention with the supplier.
- Take the lifting speed from the proposed hoist specification and the overall efficiency from the drive or mechanism calculation.
Calculation diagram
A PRACTICAL WALKTHROUGH
How to use this calculator
Set speed and efficiency
Use metres per minute for the actual lifting mode and percent for the total drive efficiency.
Compare steady power
Read the load power separately from the input power. Save the conditions alongside the result when comparing offers.
5 t load at 8 m/min
THE INPUTS
5,000 kg suspended mass, 8 m/min lifting speed and 80% overall drive efficiency.
THE RESULT
The load receives about 6.538 kW. The model requires about 8.172 kW at the drive input under steady lifting.
What does the result mean?
01
Input power is higher than load power because the entered efficiency accounts for losses.
02
The result is a steady mechanical input requirement. It does not select a motor nameplate rating, starting torque or thermal duty.
03
A faster lifting speed increases steady power in direct proportion if the other inputs stay unchanged.
Watch for this
Using motor efficiency alone as the overall efficiency while omitting the gearbox and reeving losses.
Formula & model conditions +
P_hook = m × g × v
P_input = P_hook / η; v[m/s] = v[m/min] / 60
- Constant upward speed under standard gravity.
- Acceleration, hook-block rating conventions, starting torque, thermal duty and motor reserve are outside this model.
Common questions
Can I choose the next larger motor directly from this result?
Motor selection also needs acceleration, starting, cooling, braking and the mechanism duty. Use the steady result as one input to that selection.
Does a dual-speed hoist need two calculations?
Calculate each lifting speed separately. Time spent in each mode is then needed for a duty or energy assessment.