Power Transmission Calculator
Convert transmitted power and speed into shaft torque, with a visible user-selected service factor.
Use the Power Transmission Calculator
Convert transmitted power and speed into shaft torque, with a visible user-selected service factor.
Calculations happen locally in your browser. ToolLott does not send these inputs to a server for this tool.
Preliminary planning or arithmetic calculation only. Confirm project inputs, units, operating assumptions and applicable requirements before procurement, construction or operational decisions.
How to use it
Replace the worked-example values with actual project data. Review the intermediate quantities and visible assumptions before using the result elsewhere.
How the Power Transmission Calculator works
Convert transmitted power and speed into shaft torque, with a visible user-selected service factor. The methodology below exposes the production equation, a QA-verified worked example and the boundary between this screen and detailed design.
Calculation breakdown
ToolLott will explain the current inputs and displayed result here.
Power-to-torque relation
The production engine evaluates T (N.m) = 9550 x P(kW) / rpm; design T = T x service factor. It begins by calculate base shaft torque from power and rotational speed., then multiply by the entered service factor for a screening design torque., and finally use the result only as one input to shaft/coupling selection. This keeps the calculation auditable instead of hiding design assumptions behind a single number.
T (N.m) = 9550 x P(kW) / rpm; design T = T x service factorToolLott evaluates the relationship using the entered units and full numeric precision before display rounding.
| Symbol / input | Meaning | Unit |
|---|---|---|
power | Transmitted power (kW) | user input |
rpm | Shaft speed (rpm) | user input |
serviceFactor | Service factor | user input |
Step-by-step method
- Calculate base shaft torque from power and rotational speed.
- Multiply by the entered service factor for a screening design torque.
- Use the result only as one input to shaft/coupling selection.
Worked example
Daniel, a project engineer, needs to transmit 18 kW at 900 rpm and wants the corresponding shaft torque before selecting a coupling.
Example inputs
- Transmitted power (kW): 18
- Shaft speed (rpm): 900
- Service factor: 1
Calculation / processing
Base torque = 9550 x 18 / 900 = 191 N.m.Service factor = 1.0, so design torque is unchanged.Reported base transmitted torque = 191 N.m.
Use the result as a screening or quantity-planning value and compare it with the project criteria, manufacturer data and applicable engineering requirements before making a design or procurement decision.
Assumptions
- The entered values are representative of the condition being screened and use the units shown on the page.
- The equation models only the stated relationship; omitted system effects are not silently estimated.
Limitations
- This page is not engineering certification and does not replace applicable standards, design loads, manufacturer data, site investigation or competent professional review.
- Results can change materially when real geometry, losses, transients, material properties, duty cycles, safety factors or regulatory criteria differ from the simplified inputs.
Common questions
Is this a final engineering design?
No. It is a transparent screening calculation using the entered assumptions and the stated equation.
Why does the page show assumptions and limitations?
Engineering formulas are only valid within their modelling assumptions; exposing them helps users decide what additional design checks are required.
Should I use the rounded displayed value in later design work?
Use suitable calculation precision and the governing project/standard requirements rather than relying on display rounding alone.
Methodology sources
Related ToolLott tools
A realistic way Daniel could use this tool
Daniel is a project engineer.
Daniel needs to transmit 18 kW at 900 rpm and wants the corresponding shaft torque before selecting a coupling.
The page is prefilled around the scenario data: power = 18; rpm = 900; service factor = 1. On calculation/processing it returns Base transmitted torque: 191 N.m, which ties the example to a specific checkable outcome instead of an abstract promise.
The scenario resolves to Base transmitted torque: 191 N.m. That gives Daniel the concrete quantity/text/file setting needed to transmit 18 kW at 900 rpm and wants the corresponding shaft torque before selecting a coupling, with the limits of the method still visible. The page also keeps this limitation explicit: Preliminary screening/planning calculation only.
Fictional scenario using realistic example data. For Ready tools, the worked result is tied to the tested example shown in the tool. Replace the figures with your own inputs and independently verify important professional, financial, legal, health or safety decisions.
What this calculator is for
Use it to convert transmitted power and speed into shaft torque, with a visible user-selected service factor.
It sits within ToolLott’s Mechanical collection, where you can also calculate bearing life, belt length, gear ratio, power transmission, shaft checks, thermal expansion and torque.