Cycling Speed Calculator

What Is a Cycling Speed Calculator?

A cycling speed calculator is a tool that estimates your riding speed based on:

• Cadence (RPM)
• Chainring teeth (front gear)
• Cog teeth (rear gear)
• Wheel and tire size
• Crank length (optional for setup)

Instead of relying only on a GPS bike computer, this calculator uses mechanical data from your bike setup. It calculates your theoretical speed assuming:

• No tire slip
• Flat terrain
• Industry-average wheel circumference

This makes it useful for training, bike setup comparison, and gear planning.

Key Inputs Explained

Let’s break down each field in the calculator so you know exactly what you are entering.

1. Cadence (RPM)

Cadence means how fast you spin the pedals.

• RPM stands for revolutions per minute.
• If your cadence is 90 RPM, your pedals rotate 90 times per minute.

Most riders cruise between 80 and 100 RPM. Racers often stay closer to 95–105 RPM.

Higher cadence = more pedal revolutions per minute = potentially higher speed.

2. Chainring Teeth (Front)

The chainring is the large gear attached to your crank.

Examples:

• 53 teeth (common on road bikes)
• 50 teeth (compact crank)
• 34 teeth (climbing gear)

More teeth in the front = higher potential speed (if cadence stays the same).

3. Cog Teeth (Rear)

The cog is the gear on your rear cassette.

Examples:

• 11 teeth (fast, flat riding)
• 25–32 teeth (climbing gears)

Fewer teeth in the rear = higher gear ratio = more speed per pedal stroke.

4. Wheel and Tire Size

Wheel circumference directly affects speed calculation.

The calculator includes common options like:

• 700c x 23mm (Road)
• 700c x 28mm (Endurance)
• 700c x 32mm (Gravel)
• 26" x 2.0" (MTB)
• 29" x 2.25" (MTB)
• 650b x 23mm

A larger wheel circumference means more distance traveled per revolution.

5. Crank Length

Crank length affects pedaling mechanics but does not directly change speed in this calculator.

Common sizes:

• 170mm
• 172.5mm
• 175mm

It is included for setup reference.

How the Cycling Speed Calculator Works

The calculator follows a simple step-by-step formula.

Step 1: Calculate Gear Ratio

Gear Ratio = Chainring Teeth ÷ Cog Teeth

Example:
53 ÷ 11 = 4.82

This means the rear wheel rotates 4.82 times for every pedal revolution.

Step 2: Calculate Development (Distance per Pedal Revolution)

Development = Gear Ratio × Wheel Circumference

If your wheel circumference is 2096 mm:

4.82 × 2096 = 10,102 mm
= 10.10 meters per pedal revolution

This means one full pedal turn moves you 10.10 meters forward.

Step 3: Calculate Speed

Multiply development by cadence:

Distance per minute = Development × Cadence

Then convert to km/h:

Speed (km/h) = Distance per minute × 60 ÷ 1000

The calculator also converts km/h to mph automatically.

What the Results Mean

After clicking “Calculate Speed,” you get four key metrics:

1. Speed (km/h)

Your estimated speed in kilometers per hour.

2. Speed (mph)

Same speed converted to miles per hour.

3. Gear Ratio

Displayed as a ratio like:

4.82 : 1

Higher ratio = harder gear = more speed per pedal stroke.

4. Development

Distance traveled per single pedal revolution, shown in meters.

This is extremely useful for comparing gears.

Example Calculation

Let’s say you enter:

• Cadence: 90 RPM
• Chainring: 53 teeth
• Cog: 11 teeth
• Wheel: 700c x 23mm

The result would be approximately:

• Gear Ratio: 4.82
• Development: ~10.10 meters
• Speed: ~54.5 km/h
• Speed: ~33.9 mph

That is sprint speed on flat ground.

Why Use a Cycling Speed Calculator?

Here are practical reasons riders use it.

1. Plan Training Sessions

You can test:

• What speed you reach at 90 RPM
• How different gears affect output
• Ideal cadence for endurance rides

2. Compare Gear Setups

Thinking about switching from 53/39 to 50/34?

You can compare development and see the difference before changing hardware.

3. Prepare for Races

Know your top-end speed in:

• 53x11
• 50x12
• 34x28

This helps with pacing strategy.

4. Understand Climbing vs Sprinting Gears

Smaller front ring + bigger rear cog = easier climbing
Bigger front ring + smaller rear cog = higher sprint speed

The calculator makes this clear with real numbers.

What This Calculator Does Not Consider

It is important to understand the limits.

This calculator assumes:

• No wind resistance
• No rolling resistance
• No gradient (flat road)
• No drivetrain loss

Real-world speed is often lower because of:

• Headwinds
• Hills
• Road surface
• Rider weight
• Aerodynamics

Think of it as theoretical maximum speed based on gearing and cadence.

Common Questions

What Is a Good Cadence for Road Cycling?

Most cyclists aim for 85–100 RPM on flat terrain.
Climbs may drop to 70–85 RPM.

Does Bigger Wheel Size Make You Faster?

Yes, slightly. A larger circumference means more distance per revolution. But tire width and terrain also matter.

Is Gear Ratio More Important Than Cadence?

Both matter.

• Gear ratio determines distance per pedal stroke.
• Cadence determines how many strokes per minute.

Speed = both working together.

How to Get the Most Accurate Results

To improve accuracy:

• Use the correct wheel size.
• Measure actual tire circumference if possible.
• Enter realistic cadence values.
• Compare multiple gear combinations.

If you want deeper precision, measure your real rollout by marking one wheel rotation on the ground.