Chains & Sprockets
Sprocket Teeth Calculator
Use driver tooth count and shaft speeds to estimate the driven sprocket tooth count required for your target ratio.
Inputs
Formula
Required driven tooth count
Worked example
Using the default values shown in the calculator, the same formula gives the following result. This is a quick sanity check for the calculation, not a design recommendation.
Inputs
- Driver sprocket teeth
- 20 teeth
- Driver speed
- 900 rpm
- Target driven speed
- 300 rpm
Result
- Calculated driven tooth count
- 60 teeth
Related calculators
Continue your workflow with a related calculation.
Chains & Sprockets
Sprocket RPM Calculator
Calculate driven sprocket RPM from driver RPM and sprocket tooth counts.
Chains & Sprockets
Sprocket Ratio Calculator
Calculate chain-drive speed ratio from driver and driven sprocket tooth counts.
Chains & Sprockets
Chain Length Calculator
Estimate roller-chain length in pitches from sprocket teeth, center distance, and chain pitch.
Frequently asked questions
Can a sprocket have a fractional tooth count?
No. The result is a sizing target. Choose a practical whole-number sprocket and then recalculate the actual RPM.
Should I always round to the nearest tooth?
Not automatically. Available sprocket sizes, minimum tooth-count guidance, center distance, and chain selection can affect the best practical choice.