Speed & Cadence Calculator
Full Drivetrain Calculator
* For internal gear hubs (in the “Cassette – City – Nexus hubs” section, marked with an asterisk), the most closely matching sprockets are used to approximate the hub’s gear ratios. However, due to rounding to whole numbers, some deviation (up to 5-6%) may occur, which can affect accuracy.
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How to Use
Some default values are already pre-filled in the calculator. Change them to match your setup:
- In the Chainring setup section, select how many front chainrings you have (1x, 2x, or 3x), then enter the number of teeth for each.
- In the Wheel section, choose your wheel diameter and tire width.
- In the Cassette section, select your cassette model (s – speed, i.e., the number of cogs); the rest of the fields will auto-fill.
You can leave the “Cadence” and “Settings” blocks unchanged — average values are used by default.
How the Calculator Works
Cadence
Cadence refers to how many pedal revolutions you make per minute (RPM). An optimal cadence under load is typically between 80 and 100. Dropping below 60-70 is generally discouraged due to the risk of knee problems. Exceeding 120 is difficult unless you’re a trained athlete.
Below the cadence input range, the minimum and maximum achievable speeds are displayed based on your selected drivetrain. The lowest value is calculated using the minimum cadence and easiest gear, and the highest with the maximum cadence and hardest gear.
Cassette
The dropdown list includes the most popular cassette options. The cassette gear range, step size, and average step are calculated automatically.
Shifting from a larger to a smaller sprocket increases the load. For instance, going from 45T to 40T means about 12.5% more effort to maintain speed. From 40T to 36T – about 11.1%, and so on. Mountain bike (MTB) cassettes typically have an average step of about 15% (ideally under 20%), while road cassettes average around 10%. MTB cassettes also tend to offer a wider range (largest sprocket ÷ smallest sprocket).
Drivetrain
This section provides a summary of your bike’s drivetrain performance based on the specified setup.
- Number of Gears (speeds)
- Gear Range – ratio of the hardest gear to the easiest. MTB typically has a 500-600% range, road bikes 300-400%, and gravel bikes 350-500%. On MTB setups, gear ratios below 1 are common for climbing ease.
- Wheel Circumference is calculated based on your chosen wheel diameter and tire width, factoring in tire deflection (default: 10%; adjustable in “Settings”). Set it to 0% if you don’t want deflection to be included. At 100%, only the rim is used. Accurate circumference is useful for configuring a bike computer.
- Maximum Speed is calculated using the hardest gear and your selected maximum cadence.
- Average Cadence is derived from the cadence range and used to calculate speeds for each gear in the table.
Settings
- The “Tire Deformation” field affects wheel circumference and all resulting speed values in the table and graph.
- Maximum Cadence is only used to determine max speed. For most riders, it’s unlikely to exceed 120 RPM, though elite cyclists may go higher.
- Gear Ratio Similarity is used to highlight gears with similar gear ratios in the table when using 2 or 3 front chainrings. Set between 0–10%. At 0%, only exact matches are highlighted.
Table
The table lists all gear combinations (front chainring × rear sprocket), the speed (km/h) at average cadence, and the gear ratio (front teeth ÷ rear teeth).
Gears with similar ratios (and therefore similar speeds) are color-coded according to the “Gear Ratio Similarity” setting. Due to the algorithm’s complexity, highlighting may not always be perfectly accurate.
Graph
The graph displays speed (km/h) on the vertical axis and shows all gear combinations. Each line represents the speed range of a specific gear from minimum to maximum cadence.
This visualization helps assess drivetrain efficiency. If there are large gaps between gears at your preferred cadence, it may force you out of your optimal range. This is also reflected by large (20%+) load jumps between cassette sprockets. You can use this data to adjust your gear setup or even consider switching to a simpler chainring configuration.
If you have questions, suggestions, or couldn’t find your cassette or tire size — feel free to leave a comment.