Reddit reviews Rolatape RT312 12.5-Inch Aluminum Measuring Wheel (Ft/In),Yellow
We found 2 Reddit comments about Rolatape RT312 12.5-Inch Aluminum Measuring Wheel (Ft/In),Yellow. Here are the top ones, ranked by their Reddit score.
Aluminum Measuring Wheel – light weight and durable with precision molded tire over aluminum spokePistol Grip for maximum comfort during useTelescopic Aluminum Handle lightweight and collapsible for easy storageHeavy-Duty construction for durability and long lifeKick Stand included
Best way is to use a measuring wheel - like this http://www.amazon.com/Rolatape-RT312-12-inch-Measuring-Wheel/dp/B004AXKQO8/ref=sr_1_1?ie=UTF8&qid=1394489793&sr=8-1&keywords=measuring+wheel
There is no tape, it just clicks every meter or yard. My high school didn't have a track so we did all our workouts on various stretches of road using one of these to measure.
I would not recommend an online mapping app or GPS if you want "accurately as possible." Those can be way off. Second best option would be a bike computer, which can be pretty good if you calibrate it carefully.
http://www.daftlogic.com/projects-google-maps-distance-calculator.htm
You can also use mils in a mil reticle with a known target height or a range finder. Could also use one of those wheel distance measure tool(probably the best options).
http://www.amazon.com/Rolatape-RT312-12-inch-Measuring-Wheel/dp/B004AXKQO8/ref=lp_3753421_1_2?s=power-hand-tools&ie=UTF8&qid=1420647496&sr=1-2