Gear Speed Calculator
Calculate gear speed step by step: N_out = N_in × T_driver ÷ T_driven.
In short
Formula: N_out = N_in × T_driver ÷ T_driven.
Output speed
483.3333 rpm
- Ratio
- 3 : 1
- Output rad/s
- 50.6145 rad/s
What this calculator does
Calculate gear speed step by step: N_out = N_in × T_driver ÷ T_driven. Worked example, questions and limitations included.
Use it to turn Input speed, Driving gear teeth, Driven gear teeth into a checked result you can compare, copy, or rerun with different assumptions.
The page shows the formula, a numeric worked example, and the assumptions that affect this mechanical calculation.
Inputs and what they mean
- Input speed
- — number value.
- Driving gear teeth
- — number value.
- Driven gear teeth
- — number value.
How to use it
- Enter each value in the unit shown next to the box (use the unit converter first if your numbers are in other units).
- Check the breakdown to see every intermediate step.
- Read the limitations before relying on the result.
Formula
Speeds in revolutions per minute.
Tooth counts above zero.
No slip in gears.
N_out = N_in × T_driver ÷ T_driven.
Inputs used: Input speed, Driving gear teeth, Driven gear teeth.
Worked example
1,450 rpm motor, 20:60 gears
- N_out = 1,450 × 20 ÷ 60 = 483.3 rpm.
Reading the result
The headline figure is the main answer. Any breakdown underneath shows the parts that make it up, so you can check the working and see what changes when you adjust an input.
Limitations and assumptions
- Single stage.
- Ideal, rigid gears.
- Motor slip not modelled.
- Results are estimates for planning and learning. Real designs, installations and bids must be checked by a qualified, licensed professional against the codes that apply where you work.
- The result depends on the values you enter for this gear speed calculator; it does not supply missing rates, rules, prices, dates, or assumptions for you.
Common questions
Can I use pulley diameters instead of teeth?
For belts, use the belt speed calculator; the speed ratio works the same way with diameters. Check the formula, example, and limitations on this page before using the result for a real mechanical decision.
What is the direction of rotation?
Two meshing external gears turn in opposite directions. Check the formula, example, and limitations on this page before using the result for a real mechanical decision.
Does load slow the output?
Gears don't slip, but the motor may slow under load; enter its loaded speed. Check the formula, example, and limitations on this page before using the result for a real mechanical decision.
How do I use the Gear Speed Calculator?
Enter the required values for Input speed, Driving gear teeth, Driven gear teeth. The calculator applies the formula on this page and shows the main result with any supporting breakdown so you can check the arithmetic.
What formula does the Gear Speed Calculator use?
N_out = N_in × T_driver ÷ T_driven. The visible formula section above lists the calculation path and the edge cases the page handles, so the result can be checked without relying on the form alone.
Can the Gear Speed Calculator be used for exact decisions?
Use it as a calculation aid, not as a substitute for checking the underlying rule, contract, policy, or professional advice that applies to your situation. When a result depends on local rules, personal details, prices, or dates, enter those values yourself and confirm them before acting.
Related tools
Calculate mechanical power step by step: P = W ÷ t, or P = F × v.