# Bicycling Energy Calculator

This page calculates caloric burn of a bicycle trip. Derived from Mike Landrus and Chuck Wright, with substantial modifications.

It calculates an energy expenditure due to wind resistance. Speed here is used for acceleration as well as wind speed.

Wind speed is factored in with a fudge of 43% added to Average Speed. This matches my mon/wed route, which is a figure eight with the long sides taking a crosswind. You lose more with headwind and sidewind than you gain in tailwind unless you ride twice as fast into the headwind.

It adds in the energy required to lift your weight (and the bike's) the specified altitude, and for acceleration. Assumptions include body mechanical efficiency 25%, bicycle 95% efficient, Cr of .004, Cw of 0.6 (on the drops), Surface Area of 1.1m^2 (197cm, 119kg, between standing and aero), 86F, 30% humidity, 1 atm pressure, 600' elevation, and a traffic stop every mile.

Body fat percentage is used for BMR. If this is not input, it uses the men's calculation based on height. If height is also not input, then it will assume you burn 1200kcal per day.

Rider's Height (inches)
Rider's Age (years)
Cyclist's Body Fat (Percent)
Cyclist's Weight (lbs), dressed
Bike's Weight (lbs), with water and tools
Average Speed (mph)
Wind Speed (mph). Excludes gusts.
Miles Traveled
Total Ascent
Hours (calculated)
Food Energy in kCalories ( Net work kCal or KWH or BTU )
Average Watts

References:

• http://www.lawrencevilleweather.com/heatindex.html
• http://sheldonbrown.com/rinard/aero/formulas.htm
• http://www.blog.ultracycle.net/2010/05/cycling-power-calculations
• http://www.cptips.com/energy.htm
• http://en.wikipedia.org
• http://www.analyticcycling.com/ForcesPower_Page.html
• http://chuck-wright.com/calculators/bicycle.html
• http://www.nutristrategy.com/fitness/cycling.htm
• http://www.fatcyclist.com/2011/07/26/the-fat-cyclist-explains-how-cyclists-expend-calories/
• http://www.cyclingpowerlab.com/cyclingaerodynamics.aspx
• http://www.researchgate.net/publication/51660070_Aerodynamic_drag_in_cycling_methods_of_assessment/file/e0b49517f886174690.pdf