Electric Bike Range Calculator
Estimate e-bike range from battery Wh, assist level, rider weight, terrain, and tire type.
Real-world range, not optimistic showroom numbers.
E-bike range marketing is wildly optimistic.
A bike advertised as “60 mile range” usually means a 150 lb rider, on the lowest assist level, on flat ground, with no wind, with new tires, in 70°F weather.
Real-world range for the same bike is more often 25-40 miles.
The math behind a realistic estimate is straightforward.
range_miles = (battery_Wh × usable_fraction) / wh_per_mile
Battery usable fraction is 80-90% of nameplate; lithium-ion batteries should not be deeply discharged, and most controllers cut off at 20% remaining state of charge.
For a 500 Wh battery, that is 400-450 Wh of actually-available energy.
Watt-hours per mile depends mainly on assist level, rider weight, and terrain:
- Eco / lowest assist, flat road, light rider: 8-12 Wh/mile
- Standard / tour assist, mixed terrain, average rider: 15-20 Wh/mile
- Sport / high assist, hilly terrain or 200+ lb rider: 25-35 Wh/mile
- Turbo / max throttle, headwind or steep climbs: 40-60 Wh/mile
A worked example.
Trek Verve+ 2 with a 500 Wh battery, 180 lb rider, mixed urban and hilly commute, standard assist setting.
Usable energy: 500 × 0.85 = 425 Wh.
Watt-hours per mile: 22 (mid-range standard assist with hills).
Range: 425 / 22 = 19 miles.
Trek’s published range for the same bike is 30-95 miles.
Throttle versus pedal-assist matters a lot.
Pure throttle (no pedaling) on a Class 2 bike doubles or triples the watt-hours per mile compared to pedal-assist at the same speed.
Pedal-assist supplements your effort; throttle replaces it.
If you have a throttle and use it heavily, expect 8-15 mile range from a 500 Wh battery.
A few details people miss.
Cold weather kills lithium battery capacity — at 32°F, expect 25-30% less usable energy than at 70°F.
Headwinds at 15 mph can double the watt-hours per mile compared to still air.
Tire pressure matters more than people expect: dropping from 65 PSI to 40 PSI on the same tire increases rolling resistance by 30-50%.
And mid-drive motors (Bosch, Shimano EP8, Brose) are 15-25% more efficient than hub motors at the same wattage because they leverage the bike’s gears.
If you commute and need to make it home reliably, the safe bet is to plan for 60% of the manufacturer’s stated range and treat anything beyond that as a bonus.