Energy consumption during cycling 

Speed 
km/hr 

Cycling time t 
min 
Weight of cyclist 
kg 
Weight of the bicycle 
kg 
Rolling
resistance coefficient C_{r} 
 
Air
resistance coefficient C_{w} 
 
Frontal surface area A_{f} 
m^{2} 
Uphill
slope k 
% 

C_{w}·A_{f} 
m^{2} 
Air resistance F_{air }= ½
ρ v^{2 }C_{w }A_{f} 
N 
Rolling resistance F_{rol} = m_{tot} g C_{r} 
N 
Force for climbing F_{climb} = m_{tot} g
sinφ 
N 
Energy per minute E = F_{tot} v t, t=60 s 
kJ/min 
kJ/min 
Energy "burned" per minute ^{1)} 
kJ/min 
kcal/min 
Efficiency of the cyclist 
% 

Driving power P = F v 
W 

Energy delivered E = P t 
kJ 
kcal 
Energy consumed (burned) ^{1)} 
kJ 
kcal 
^{1)} The energy burned is approached using
reference tables of different web sites like
source1.
Reference values are correlated to the energy delivered by
cycling.
^{2)} The dimension kcal (1 kcal=4.19 kJ) is the old
dimension for Joules.
^{3)} The energy delivered by the muscles is small
compared to the energy burned, only 12.5% with a cycling
speed of 20 km/h and 20% at 30 km/hr.
^{4)} In comparison, the efficiency of a large
electric powered motor is about 90%, of a diesel engine 40%
and a petrol engine 25%. In the calculation of the
efficiency of an electric powered motor one should consider
the efficiency of power stations that transform fossil fuels
in electricity.
The efficiency of a coal power plant is about 40%, that of a
gas power plant 45%. This actually reduces the efficiency of
an electric powered motor to 0.45 0.9 = 40%, not more than
that of a diesel engine. 

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