How this instrument works
An e-bike's range comes down to a simple ratio: how many watt-hours (Wh) of battery capacity you have, divided by how many watt-hours the bike consumes per mile. That consumption rate isn't fixed — it swings widely with terrain, assist level, rider weight, and motor type, which is why e-bike range estimates are always given as a range rather than a single number. This calculator uses three representative consumption scenarios — roughly 14 Wh/mile for efficient riding, 20 Wh/mile for average mixed conditions, and 26 Wh/mile for extreme hilly or heavy-load riding — spanning the commonly published 10-30 Wh/mile efficiency range for e-bikes.
Several factors push consumption toward the high or low end of that range. Flat terrain, a lighter rider, eco/low-assist mode, and good tire pressure all reduce Wh/mile; hills, higher assist levels, a heavier rider or cargo load, headwinds, and lower tire pressure all increase it. Motor type matters too — mid-drive motors are generally more efficient than hub motors, particularly on climbs, since they can leverage the bike's own gearing.
Because actual consumption depends on so many rider- and route-specific variables, treat this calculator's output as a planning estimate rather than a guaranteed number for a specific ride. Manufacturers' advertised maximum ranges are often measured under best-case conditions (lowest assist, flat ground, light rider) that don't reflect typical real-world riding — the 'average' scenario here is usually a more realistic planning baseline than a spec sheet's headline figure.
- Enter Battery capacity in watt-hours (Wh) — check your e-bike's spec sheet or battery label if you're not sure.
- Select a Riding conditions scenario — Efficient, Average, or Extreme — based on your typical terrain, assist level, and load.
- Read Estimated range in miles.
- Read Estimated range in kilometers, the same figure converted.
- Re-run the calculation for a different scenario if your ride will mix conditions (for example, hilly outbound, flat return) to bracket a realistic range.
Worked example — a 500 Wh battery across three riding scenarios
Enter 500 for battery capacity and select Efficient (≈14 Wh/mile) riding conditions — flat terrain, eco mode, a lighter rider. Range comes out to 500 / 14 = 35.7 miles (about 57.5 km).
Switching to Average conditions (≈20 Wh/mile) with the same 500 Wh battery drops the estimate to 500 / 20 = 25.0 miles, and Extreme conditions (≈26 Wh/mile — hills, max assist, a heavier rider or cargo) brings it down further to 500 / 26 = 19.2 miles. That roughly 35-to-19-mile spread from the same battery, just from changing terrain and assist level, is exactly why e-bike range is best planned as a range rather than a single fixed number.
Questions
Why does my e-bike's actual range never match the manufacturer's advertised number?
Advertised ranges are frequently measured under best-case conditions — flat ground, lowest assist level, a relatively light test rider, ideal weather — that don't reflect how most people actually ride. Hills, higher assist settings, a heavier rider or added cargo, headwinds, and cold weather (which reduces battery efficiency) can all push real-world consumption well above the spec-sheet figure. Using this calculator's 'average' or 'extreme' scenario, rather than assuming the manufacturer's headline number, generally gives a more realistic planning estimate.
What Wh/mile consumption should I use if I don't know my e-bike's actual efficiency?
If you've never tracked it, the 'Average' scenario (about 20 Wh/mile) is a reasonable default for mixed terrain with moderate assist use. If you know your typical ride is mostly flat with light assist, lean toward 'Efficient'; if it's hilly, high-assist, or you regularly carry cargo or a passenger, lean toward 'Extreme.' Many e-bike apps and displays also show real-time or trip-average Wh/mile (or Wh/km) consumption, which is the most accurate input if you have access to it.
Does assist level have a big effect on range?
Yes — assist level is one of the largest single factors in e-bike range. Riding in eco or low-assist mode makes the motor contribute less power (and draw less battery), so your own pedaling does more of the work, while turbo or high-assist modes draw significantly more battery for the same distance. Many riders can roughly double their range by dropping from a high assist setting to eco mode on the same route.
Do hub-motor and mid-drive e-bikes have different efficiency?
Generally, yes — mid-drive motors tend to be more energy-efficient than hub motors, particularly when climbing, because a mid-drive can use the bike's own gearing to keep the motor operating in an efficient range regardless of speed or grade. Hub motors are simpler and often cheaper but typically consume more Wh/mile on hilly terrain since they lack that gearing advantage. If your bike uses a hub motor and you ride hilly terrain, leaning toward the 'Average' or 'Extreme' scenario is usually more realistic.
Does cold weather reduce my e-bike's range?
Yes — lithium-ion batteries, which power virtually all modern e-bikes, lose some effective capacity in cold temperatures, meaning the same battery can deliver less usable energy on a cold-weather ride than the identical trip on a mild day. Riders in cold climates often see a noticeably shorter range in winter for the same route and assist settings, which is a separate effect from the terrain/assist-level factors this calculator's scenarios primarily represent.