Power and Speed

Our patented resistance calculator allows you to personalize your cycling simulation anywhere in the solar system.

Explore the relationship between your cycling power (wattage) and speed. Move your cursor over the graph, or tap on it, to explore specific points. Modify the fields below and the graph will update.

Units:    imperial    metric

Personalized Simulation: Crested Butte's 401 Trail

User Data

Rider and Bike Parameters
Weight of Rider (lbs):
Weight of Bike (lbs):

Total weight W (lbs): 182.00

Select Your Shirt Size:
Drivetrain loss Loss dt (%)

Type of Bike: Type of Tire:

Brand of Tire (Road):

PSI of Tire: (66)
Crested Butte

The 401 trail is a classic ride in the town where Colorado mountain biking was born. Filmed during peak wildflower season, this ride has flowing single track around alpine lakes and through alpine meadows before transitioning through aspen groves. This is nature at her finest.


Environmental parameters

Crested Butte 401 Trail
Temperature (°F):
Air pressure (inHg):
Dew point (°F):
Distance from Sun (MI): rho (kg/m 3) = 1.2260 rho (lb/f 3) = 0.076538



If you apply 200 watts of power, you will ride at groundspeed velocity 20.81 mph .


If you want to ride at groundspeed velocity 22 mph , you must apply 231.43 watts of power.

Wind Speed:

0 mph

Fun Facts

Earth is not a perfect sphere as it’s flattened at the poles and bulging at the equator creating a shape known as oblate spheroid. This means the highest point above the Earth’s center is Mount Chimborazo in Ecuador, near the equator (not Mt. Everest). Locations at the poles are closer to space than locations at the equator.

A Martin sunset has a distinct blue tint. This is because the fine dust in the Martian atmosphere scatters sunlight in a way that emphasizes blue light for a unique and visually striking quality.

Sunlight on Mercury is 11 times brighter than Earth.

Venus experiences a phenomenon called “super-rotation” in its atmosphere. The clouds (filled with sulfuric acid) where the winds can reach speeds of up to 225mph (360 kilometers).

Jupiter has a massive magnetosphere due to it’s rapid rotation and presence of metallic hydrogen. If it was visible, it would appear larger than the Moon.

Due to Saturn being mostly composed of hydrogen and helium, if you were to place it in water it would float.

Uranus is tilted at an extreme angle of about 98 degrees causing it to rotate on its side where one pole is facing the sun while the other is not.

Driven by the planet’s internal heat, winds can reach speeds of 1,300 mph / 2,100 kph.

Pluto’s atmosphere is dynamic as when it’s close to the Sun it’s frozen surface ices melt, creating a temporary atmosphere.

The Moon is tidally locked, so Earth always see’s the same side of the Moon.

Computational Graph:

Air Density Calculator:

This air density calculator lets you estimate one of the parameters used in cycling power models ("rho"). Rho used specifically when estimating aerodynamic drag forces. To calculate, you will need to provide three parameters: air temperature, air pressure, and dew point. You should be able to look up these three parameters for your region from most weather web sites.

For more information about the assumptions and formulas used, click here.