Your ride
One-way miles, the hills, and whether the air is cold. We cut each class's advertised range, then compare it with the trip.
After the cut
What we cut, and why
A paved mild day keeps about 70 percent of the advertised miles. Some hills keep 55 percent. Steep or sustained climbs keep 40 percent. Air around 40°F or below takes another 25 percent off, because the battery gives up capacity. The default trip is there and back. If you can charge at the other end, we only count one way.
Class miles, not a dyno sheet
Each bike here is a class with a typical advertised range, not a lab result for this year's listing. A 'covers it' result still means you open amazon.com and confirm the battery watt-hours on the page you are about to buy. A 'short' result means that class is the wrong job, even if the listing says 50 miles.
How the cut works
Why not use the range printed on the listing?
That number is usually the best case: light rider, flat ground, low assist, warm battery, no stops. A commute is the opposite. The check applies the same cut to every class so you can compare them.
How much does cold actually take?
We take 25 percent off when the air is about 40°F or below. That is a planning cut, not a temperature chamber. If your winter ride is the one you must finish, treat a tight result as a no.
What if I can charge at work?
Check that box. The tool then compares usable miles with the one-way distance instead of the round trip. You still want a few miles left so you are not arriving on an empty pack.