Cycling Calories Calculator
The Cycling Calories calculator shows how many calories you burn on a ride based on speed, duration, body weight, and drafting—useful for fueling plans, weight goals, and pacing on flats.
This calculator lets us enter steady speed, ride time, weight, and a drafting level to estimate both total kcal and an average power figure in watts. The goal is a fast, practical estimate for road cycling without a power meter. If we’d rather compute it manually, we outline the aerodynamic and rolling formulas below.
Enter steady speed, ride duration, body weight, and a drafting level. We estimate total calories and average power using a simple physics model for rolling resistance and aerodynamics on level road.
Flat road, steady speed. Wind, temperature, altitude, bike fit, and position can change actual power and calories substantially.
Results interpretation
How it works
We estimate cycling power from rolling resistance and aerodynamic drag, then convert mechanical work to metabolic calories.
Formulas, assumptions, limitations
Rolling resistance. P<sub>rr</sub> = Crr × m × g × v. Heavier systems and rougher surfaces increase this term.
Aerodynamics. P<sub>aero</sub> = ½ × ρ × CdA × v³. Drafting scales CdA (light −10%, moderate −20%, heavy −30%).
Total & drivetrain. P = (P<sub>rr</sub> + P<sub>aero</sub>) × 1.03 to reflect drivetrain losses.
Calories. Metabolic kcal = (P / efficiency) × time ÷ 4186.8. We use gross efficiency ≈ 24% as a practical average.
Use cases & examples
P ≈ 170 W → kcal/min ≈ (170/0.24)/69.78 ≈ 10.1 → total ≈ 606 kcal.
P drops from ~175 W (solo) to ~150 W (draft). kcal ≈ (150/0.24)×540/4186.8 ≈ 807 kcal.
CdA −30% can trim ~50–70 W depending on conditions, reducing calories by ~15–25% over the same duration.
Cycling Calories FAQs
Why does a small speed change swing calories so much?
Aerodynamic power grows with the cube of speed. A 10% speed increase can raise required watts by ~30%, increasing kcal quickly.
Is drafting reduction realistic?
Estimates vary with spacing and wind. We model light/moderate/heavy as ~10/20/30% aero savings to keep planning simple.
What if I ride hills or facewinds?
Climbs add gravitational work; winds change effective airspeed. Our flat, still-air model is a baseline for steady rides.
Does bike weight matter?
On flats, aerodynamics dominates. Extra mass modestly raises rolling resistance; on climbs, weight matters far more.
Why 24% efficiency?
Human gross efficiency on the bike typically ranges ~20–25% for steady endurance efforts. We use 24% as a pragmatic middle.
Understanding cycling energy: where the watts go
On flat roads at steady speed, most of our effort goes into pushing air out of the way. That aerodynamic cost rises with the cube of speed, which is why an extra mph late in a ride can feel so expensive. Rolling resistance—how much the tires deform and lose energy against the surface—adds a smaller, linear term that grows with system mass and speed.
Position, CdA, and free speed
Our frontal area and posture determine CdA. Narrow elbows, a flat back, and a clean front end lower CdA and cut aero power dramatically—often more effective than shaving grams from the bike. Clothing flapping in the wind or a tall stack height can raise CdA and cost minutes over long distances.
Drafting and group dynamics
Sitting in a wheel reduces the pressure difference across our body and effectively lowers CdA. In a tidy paceline, savings of 20–30% are common, though they fluctuate with crosswinds and gaps. Learning to hold a safe, steady following distance is one of the biggest gains a new road cyclist can make.
What calories mean for fueling
Calories reflect metabolic energy. Because only a fraction of our chemical energy becomes mechanical work at the pedals, our total kcal is roughly four times our mechanical work in kilojoules. For endurance rides, planning 30–90 grams of carbohydrate per hour—adjusted for intensity and gut tolerance—helps maintain power output.
Terrain, wind, and temperature
Hills add gravitational work proportional to vertical gain. Headwinds raise effective airspeed; tailwinds do the opposite. Cold dense air increases drag, while hot thin air reduces it. These environmental factors can easily swing real energy ±20% compared to a calm, temperate baseline.
Practical pacing tips
- Hold a smooth line and stable power in groups to maximize drafting benefit.
- Invest in position: narrow your profile and tame loose fabric before seeking marginal gear gains.
- Use lap averages to avoid surging; spikes waste energy against v³ aero costs.
- Fuel early—don’t chase a deficit late in the ride.
- On windy routes, ride conservatively into headwinds and capitalize on tailwinds.