Tread Lightly Bike Calculator Assumptions
Fact: 40% of trips by car are within 2 miles from home & 50% of commutes are less than 5 miles. The first two miles while an engine is cold cuts mileage by 40% and depreciates a car more quickly than constant long distance operation.
 Thus we figure with gas at $3.00 a gallon, that a 20 mpg car, driving city miles with a warm engine, costs 15 cents per mile plus 3 cents for other maintenance, totaling 18 cents per mile.
 With the cold car penalty a 20 mpg car is actually getting about 12 mpg the first two miles. At $3.00 a gallon, this is 25 cents per mile, plus a little more for maintenance (5 cents) means a total of 30 cents per mile.
 The Tread Lightly Bike Calculator includes these assumptions to calculate cost savings. For the first two miles of a commute, we provide a 30 cent per mile savings over a car and then 18 cents for each additional mile. We know of no other bike saving calculator that includes this important consideration.
 We believe the true economic value of cycling short distances can only be appreciated incorporating the cold car penalty.
 The calculator has an option to automatically add your commute miles, which is done each night. All you have to remember to do is delete miles you may not have been able to ride. If you don’t want to use this feature, don’t enter or save any number.
We know that mileage varies among vehicles, and the price of gas changes almost daily. We tried to hit somewhere in the middle for each. How you drive, what you drive, what you pay for gas, and how much you owe on a car all influence any calculator. However, the greatest factor influencing savings is the value of substituting a short distance trip by car to one by bike.
These are minimal personal financial benefits from cycling. Eliminating a car doubles your savings to about 60 cents per mile. When you add external costs from pollution caused health problems, environmental damage, cost of infrastructure, the cost of oil supply lines borne outside of gas taxes, the cost savings is doubled again. Thus the true cost of fuel based transportation mitigated by substituting cycling, equals at a low end, at least $1.20 per mile! Click for calculator. Click for feedback.
