Cycling Speed & Distance Calculator

Cycling performance is described by two primary metrics: speed (how fast you travel) and power (how much energy you produce). Both are connected through the physics of cycling resistance.

Speed from distance and time: Speed (km/h) = Distance (km) ÷ Time (hours) Speed (mph) = Distance (miles) ÷ Time (hours)

Worked example: You complete a 45 km ride in 1 hour 45 minutes (1.75 hours): Speed = 45 ÷ 1.75 = 25.7 km/h

Speed benchmarks:

• Casual recreational: 15–20 km/h (9–12 mph)
• Fitness rider: 20–25 km/h (12–16 mph)
• Club rider: 25–32 km/h (16–20 mph)
• Amateur racer: 32–40 km/h (20–25 mph)
• Tour de France stage average: 40–45 km/h (25–28 mph)

Why average speed is a bad way to compare rides

It is the number everyone quotes and it tells you almost nothing on its own. Average speed folds together fitness, wind, gradient, traffic lights, road surface, whether you sat in a group, and how much of the ride you spent coasting. A 28 km/h solo ride into a headwind is a far harder effort than 34 km/h in the back of a fast group, and the second one looks better on paper.

Two things make the number more honest. Use moving time rather than elapsed time, which every bike computer offers and which stops a coffee stop from wrecking the figure. And compare rides on the same route, in similar weather, rather than against other people.

The cube law, and why speed gets so expensive

At moderate speeds air resistance dominates, and the power needed scales roughly with the cube of speed:

Power ≈ k × Speed³

Doubling your speed takes about eight times the power. In practical terms, going from 25 to 30 km/h costs roughly 75% more watts than the 5 km/h before it did. This is why a small aerodynamic gain is worth more than a large weight saving on the flat, and why riders who want to go faster spend money on position before they spend it on wheels.

Gradient flips that logic. On a climb steep enough that speed drops below about 15 km/h, air resistance almost vanishes and gravity takes over, at which point weight matters and aerodynamics barely register.

To work out the watts behind a given speed, use the cycling power calculator. For the calories, use the cycling calorie calculator, which asks for effort level rather than trying to infer it from speed alone.