Cycling gear ratios determine how far your bike travels with each pedal revolution — critical knowledge when choosing gearing for climbs, flats, or sprints. This gear calculator builds a complete chart for your chainring and cassette combination, showing speed at your target cadence, rollout distance, and gear inches for every possible gear combination. Works for road, gravel, and mountain bikes.
Drivetrain Setup
Comma-separated: 50,34 for compact double
Comma-separated, smallest to largest
Quick Presets
How to Use the Cycling Gear Calculator
Choosing the right gearing for your bike is one of the most impactful equipment decisions you can make. Too hard a gear and you grind slowly uphill; too easy and you spin out on descents. This cycling gear calculator maps your complete drivetrain so you can see exactly what speed you will achieve in every combination at your target cadence.
Step 1: Enter Your Chainrings
Enter the number of teeth on your front chainring(s), separated by commas. A typical compact road double is 50,34. A standard racing double is 53,39. For a 1× drivetrain (single chainring), enter just one number, e.g. 42. You can find your chainring size stamped on the chainring itself or in your bike's component spec sheet. Use one of the quick presets at the bottom of the form to auto-fill common setups.
Step 2: Enter Your Cassette
Enter the tooth count of every cog in your cassette, separated by commas from smallest (hardest) to largest (easiest). For example, a standard 11-28 road cassette might be 11,12,13,14,15,17,19,22,25,28. Check the cassette itself or look up your groupset's specification. A wider range cassette (e.g. 11-34) gives more climbing range; a closer ratio cassette (e.g. 11-23) gives finer speed control for racing.
Step 3: Select Wheel and Tyre Size
Wheel circumference directly affects how far you travel per pedal stroke. A 700c × 25mm road tyre has a different circumference than a 26" × 2.0" mountain bike tyre, producing different speeds at the same cadence and gear ratio. Select your wheel and tyre combination from the dropdown. If your tyre size is not listed, the closest option will give a reasonable approximation.
Step 4: Set Your Target Cadence
Cadence is how many times you pedal per minute. Use the slider or type your preferred cadence. Most road cyclists target 85-100 RPM for efficient aerobic riding. Mountain bikers often use 70-85 RPM on technical terrain. The calculator shows the speed you achieve in every gear at exactly this cadence, helping you identify which gear gives your target road speed.
Understanding the Chart
The gear chart shows one row per chainring and one column per cassette cog. Each cell shows speed at your chosen cadence. The gear ratio (chainring ÷ cog), rollout distance (metres per pedal revolution), and gear inches are also shown. Colour coding highlights very low gears (green, for climbing) through to high gears (indigo, for sprinting). Cross-chained combinations (large front + large rear, or small front + small rear) are flagged — they cause excessive chain wear and should be avoided in normal riding.
FAQ
Is this cycling gear calculator free?
Yes, completely free with no signup required. All calculations run locally in your browser and no data is ever sent to a server.
Is my data safe and private?
Yes, all calculations happen entirely in your browser. Your gear configuration data is never transmitted to any server or stored after you close the page.
What is gear ratio and why does it matter?
Gear ratio is the number of rear wheel rotations per pedal revolution, calculated by dividing chainring teeth by cog teeth. A higher ratio (e.g. 53/11 = 4.82) means more distance per pedal stroke — great for fast descents and flat sprints. A lower ratio (e.g. 34/32 = 1.06) makes climbing easier at the cost of top speed. Understanding your gear ratios helps you choose the right gearing for your terrain and fitness level.
What is rollout distance?
Rollout (also called development) is the distance your bike travels with each complete pedal revolution in a given gear. It is calculated as gear ratio × wheel circumference. A higher rollout means more distance covered per pedal stroke. Rollout is especially useful for comparing gear effectiveness across different wheel sizes or when setting up a new drivetrain.
What are gear inches?
Gear inches is an older imperial measure of effective drive wheel diameter, dating from penny-farthing bicycles. It equals gear ratio × wheel diameter in inches. A gear inch of 100 means you travel the equivalent of one rotation of a 100-inch diameter wheel per pedal stroke. Gear inches make it easy to compare gearing across bikes with different wheel sizes.
What is a good cadence for cycling?
Most road cyclists target 85-100 RPM as an efficient cadence that reduces muscle fatigue and keeps heart rate steady. Mountain bikers often pedal at 70-85 RPM on technical terrain. Beginners tend to push bigger gears at 60-75 RPM (grinding), which increases knee strain over time. The calculator shows your speed at any target cadence so you can choose gearing that lets you spin in your preferred range.
How do I choose the right cassette for climbing?
A common rule of thumb is to have at least a 1:1 gear ratio (equal chainring and cog teeth) for steep climbs. For hilly road riding, a compact chainset (50/34) with an 11-32 cassette provides a climbing range of 1.06:1. For very steep gravel or mountain terrain, many riders now use a 1× drivetrain with a 42T chainring and 10-51T cassette for a lowest ratio of 0.82:1. Enter your setup in the calculator to see your full range.
Does wheel size affect speed calculations?
Yes — larger wheels travel further per rotation, so the same gear ratio produces higher speeds on a 700c road wheel than on a 26-inch MTB wheel. This calculator supports 700c (road), 650b (gravel), and 26-inch (MTB) wheels with common tire widths, automatically adjusting the circumference used in speed and rollout calculations.