Bike Cadence Speed Calculator

Bike Cadence & Speed Calculator

Calculate cycling speed from cadence and gear ratio, or find required cadence for a target speed. Essential for optimizing pedaling efficiency and gear selection.

Last updated: March 2026 | By Patchworkr Team

Speed & Cadence Calculator

Gear Ratio

2.94

Result

33.4 km/h (20.7 mph)

Cadence Zones & Speed Reference (50x17 Gear)

RPMCategorySpeedBest For
70-80Climbing17-19Steep grades
80-100Endurance19-24Long distance
90-110Sweet Spot21-26Group riding
110-130Threshold26-31Performance
130+Sprint31+Final kick

Note: 90-100 RPM is most efficient for sustained riding. Higher cadence reduces joint stress.

What is Cadence?

Cadence is your pedaling rate measured in revolutions per minute (RPM). It's one of the three variables (along with gear ratio and wheel size) that determine cycling speed. Optimal cadence varies by discipline: recreational riders average 60-70 RPM, trained cyclists maintain 80-95 RPM, and professional racers often exceed 100 RPM during attacks.

The relationship between cadence, gearing, and speed is mechanical: Speed = (Cadence × Gear Ratio × Wheel Circumference × 60) ÷ 1000. This calculator solves this equation bidirectionally—find speed from a given cadence, or determine the cadence needed to achieve a target speed in a specific gear.

Understanding this relationship helps you select appropriate gears for terrain and intensity. Climbing steep gradients requires low gears (small front, large rear) to maintain 70-80 RPM. Descending or time trialing uses high gears (large front, small rear) to sustain 90-100 RPM at high speeds.

How to Use This Calculator

Step 1: Choose whether to solve for Speed (given cadence) or Cadence (given target speed). Most cyclists use this to plan gear selection for target speeds.

Step 2: Enter your chainring teeth count (front gear). Standard compact is 50/34, standard double is 53/39, triple is 50/39/30.

Step 3: Enter your cassette cog teeth count (rear gear). Modern cassettes range from 11t to 32t. Check the specific cog you're using.

Step 4: Input wheel circumference in meters. Standard road (700×23c): 2.096m, road (700×25c): 2.105m, mountain (29×2.2"): 2.29m. Measure precisely by marking the tire and rolling one full revolution.

Step 5: Enter cadence (if solving for speed) or target speed (if solving for cadence). The calculator shows the result instantly.

Formula

  • Speed (km/h): (Cadence × Gear Ratio × Wheel Circ × 60) ÷ 1000
  • Cadence (RPM): (Speed × 1000) ÷ (Gear Ratio × Wheel Circ × 60)
  • Gear Ratio: Front Teeth ÷ Rear Teeth

Example Calculation

Scenario: You want to ride at 35 km/h on flat terrain. Your bike has a 52t chainring and 15t cog, with 700×25c wheels (2.1m circumference). What cadence do you need?

Target Speed

35 km/h

Gearing

52 / 15

Wheel Circumference

2.1 m

Gear Ratio

3.47

Calculation:

Cadence = (35 × 1000) ÷ (3.47 × 2.1 × 60)

Cadence = 35000 ÷ 437.22

Required Cadence: 80 RPM

This is a sustainable cadence for most trained cyclists. If you want to maintain 90 RPM at this speed, shift to a harder gear (e.g., 52/14).

Frequently Asked Questions

What's the optimal cadence for cycling?

80-100 RPM for road cycling, 70-90 RPM for mountain biking. Elite cyclists maintain 90-95 RPM. Higher cadence reduces muscular load but increases cardiovascular demand.

How do I measure wheel circumference?

Mark your tire and ground, roll forward one full revolution, measure the distance. Or use standard values: 700×23c = 2.096m, 700×25c = 2.105m, 700×28c = 2.136m.

Why does cadence matter?

Optimal cadence maximizes efficiency and power output while minimizing fatigue. Too low (50-60 RPM) stresses muscles; too high (110+ RPM) wastes cardiovascular capacity.

How accurate is this calculator?

Highly accurate for theoretical speed. Real-world speed is affected by wind, rolling resistance, drivetrain efficiency (~97%), and power output.

What gear should I use for climbing?

Use lower gears (e.g., 34/28) to maintain 70-80 RPM on steep climbs. This preserves leg freshness and prevents premature fatigue.

Can I increase my cadence?

Yes. Practice high-cadence drills (100-110 RPM) for 5-minute intervals. Over weeks, your neuromuscular system adapts to faster pedaling.

Why do pros pedal so fast?

Higher cadence (90-100 RPM) reduces muscular strain by distributing load across more pedal strokes. This improves endurance in multi-hour races.

What if my speed doesn't match?

Check wheel circumference accuracy, tire pressure (affects rolling circumference), and drivetrain condition. Worn chains reduce efficiency by 3-5%.

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