What gear should I ride?
Meet your next hill with the right gearing. Set your power, gradient and preferred cadence. See your road speed, the best actual gear, and what happens when the road changes.
Make the road yours
Your weight affects the speed you can sustain on a climb.
Shimano 105 · 50/34 · 11–34
Use my own sprocket sizes
See the difference immediately
Assuming 80 rpm preferred cadence and no wind
Try the 10% gradient button or change your weight and watch these results update.
View full gearing analysisAdjust cadence and wind 80 rpm · no wind by default
Bicycle and resistance settings
KA is the combined aerodynamic factor (½ × air density × CdA). Air density is included in this factor. This model uses 97% drivetrain efficiency.
Your gear, at a glance
See your gear options
These are practical options near your target cadence, with extreme cross-chaining discouraged. Select one to see its cadence at your estimated speed.
Where the watts go
At estimated speedA steady-state estimate, not a prediction of fitness or safety. Negative hill watts mean gravity is helping. Calculations include an assumed 97% drivetrain efficiency; the existing calculators are unchanged.
Real calculations. Clear recommendations.
We calculate the steady speed supported by your power after accounting for wind, rolling resistance and climbing. Then we check the actual cassette and chainrings for a gear near your preferred cadence, avoiding extreme chainlines where practical. If no gear is close, we'll tell you rather than pretend the gearing is ideal.
How to choose bicycle gearing for a climb
Start with the power you can realistically sustain, not a speed you hope to reach. On an uphill road, gravity adds to rolling resistance and aerodynamic drag. The adviser first estimates a sustainable road speed for your entered weight, power and gradient, then compares your cassette and chainrings against your preferred pedalling cadence.
Example: 34-tooth chainring and a 34-tooth sprocket
A 34T front ring with a 34T rear sprocket gives an overall 1.00:1 ratio: the rear wheel makes one revolution per crank revolution. Swapping the rear sprocket to 40T lowers that ratio to 0.85:1, reducing road speed at the same cadence by 15%. It does not reduce the power required to travel at the same speed; it lets you pedal faster with less average crank torque at the slower speed.
Check the predicted climbing cadence in your lowest gear. The numbers describe gearing, not whether a particular chain, derailleur or hub is mechanically compatible. For a fuller explanation of cadence and resistance coefficients, see the cycling cadence guide on the Home page.