Cycle to Work Calculator

Inputs

Enter your route and conditions. Advanced fields refine physics realism.

Example data table

These sample values illustrate typical urban commuting conditions.

Formula used

This calculator estimates steady-state cycling power by summing three main resistive forces:

• Rolling resistance: Frr = Crr · m · g
• Climbing (grade): Fgrade ≈ m · g · (elevation_gain / distance)
• Aerodynamic drag: Fdrag = 0.5 · ρ · CdA · vrel2

Total force is F = Frr + Fgrade + Fdrag, and wheel power is Pwheel = F · v. Pedal power accounts for drivetrain efficiency:

Ppedals = Pwheel / ηdrive

Mechanical energy per trip is E = Ppedals · t. Calories are estimated using human efficiency and 1 kcal = 4184 J.

How to use this calculator

1. Enter your one-way distance, weekly commuting days, and your usual speed.
2. Add total mass and elevation gain to reflect bike load and route hills.
3. Refine realism with wind, rolling resistance, drag area, and efficiencies.
4. Optionally enter driving assumptions to estimate weekly CO₂ and fuel savings.
5. Press Calculate to see results above the form and download reports.

Professional guide

1) What the calculator measures

This tool estimates steady cycling performance using forces, power, energy, and time. It models rolling resistance, road grade from elevation gain, and aerodynamic drag from air density and drag area. Outputs include average pedal power, trip duration, mechanical energy, and estimated dietary calories.

2) Why speed changes power so quickly

Aerodynamic drag rises with the square of relative airspeed, while aerodynamic power rises roughly with the cube of speed. For many commuters, moving from 18 to 24 km/h can increase required power far more than the time saved. Wind matters because headwind adds directly to relative airspeed.

3) Typical parameter ranges for commuting

Urban tires often fall near Crr 0.004–0.010 depending on pressure and surface. Drag area (CdA) commonly ranges 0.30–0.60 m²: upright posture is higher, tucked posture is lower. Air density near sea level is about 1.2 kg/m³ and decreases with altitude and heat.

4) Hills, mass, and elevation gain

Climbing work scales with total mass and elevation gain. Adding 10 kg of load increases climbing power on the same route, especially when elevation gain is concentrated. The calculator converts your one-way elevation gain into an average grade, giving a useful first-order estimate for commuting routes with mixed slopes.

5) Drivetrain and human efficiency

Drivetrain efficiency typically sits in the mid-to-high 90% range, so chain cleanliness and alignment still matter. Human efficiency is lower because metabolic energy is converted into mechanical output; a practical range is about 18–26%. This is why calorie estimates can exceed the mechanical energy at the pedals.

6) Interpreting the power breakdown

Rolling power tends to dominate at low speeds, climbing power dominates on hilly routes, and aerodynamic power dominates at higher speeds or in wind. If aerodynamic power is the largest slice, improving posture, clothing, and speed targets often produces more benefit than changing mass or tires.

7) Weekly time, calories, and training consistency

Weekly totals scale linearly with commuting days and round-trip distance. A 10 km one-way ride at 5 days per week equals 100 km weekly. That consistency can meaningfully raise weekly energy expenditure and aerobic volume. Use the weekly hours and calories to plan recovery, fueling, and sustainable effort.

8) Emissions and fuel savings context

The driving comparison converts your weekly distance into avoided emissions using a grams-per-kilometer factor, and estimates fuel avoided using liters per 100 km and fuel price. Results are scenario-based: vehicle type, traffic, and grid intensity can shift the true impact. Treat the savings as an informed estimate, not a guarantee.

FAQs

1) Why does headwind increase effort so much?

Drag depends on relative airspeed. A 10 km/h headwind added to your riding speed can raise drag force sharply, so aerodynamic power rises quickly and your required pedal power increases noticeably.

2) What should I enter for CdA?

Use 0.45 m² as a general commuter default. Upright city posture may be 0.50–0.60 m², while a more tucked position can be 0.30–0.40 m².

3) How do I estimate elevation gain?

Use a mapping app to read total climb for the one-way route. If you only know net elevation change, it may underestimate effort because rolling climbs still require extra energy.

4) Are the calorie numbers accurate?

They are estimates based on human efficiency and steady riding. Temperature, stop-and-go riding, fitness, and measurement error can shift true calories. Use them for planning, not medical precision.

5) What rolling resistance value is reasonable?

For smooth pavement and good tires, try 0.004–0.006. For rough roads, heavy tires, or low pressure, 0.007–0.010 is more realistic.

6) Why is climbing shown as average grade?

The calculator distributes elevation gain across the distance to estimate a mean grade. Real routes vary, but the average grade captures first-order climbing work and keeps inputs simple.

7) How should I use the weekly savings outputs?

Adjust the car emissions factor and fuel use to match your vehicle. The weekly CO₂ and fuel estimates help compare scenarios and set goals, but real-world results vary with traffic and driving style.