E-bike range calculator
How far can you go on one charge, and what battery does your trip need? The estimate counts the terrain, the assist level, your weight and the battery's condition.
If only the voltage and amp-hours are given, multiply them: 36 V × 13.9 Ah = 500 Wh.
Without the bike.
0 for a new battery.
Needs a licence, insurance and a helmet.
Example
A 625 Wh battery, rolling terrain, sport assist, 95 kg, surface: gravel, temperature: 0–10 °C, after 300 charges.
- 1. Consumption7 Wh/km (rolling) × 1.3 (assist) × 1.08 (weight) × 1.15 (surface) = 11.2 Wh/km
- 2. Usable capacity625 Wh × 0.85 (cold) × 0.84 (age) = 445 Wh
- 3. Range445 Wh ÷ 11.2 Wh/km ≈ 40 km, band 34–46 km
- 4. Comfortable daily trip40 km ÷ 1.35 (reserve) ≈ 29 km
Example: what battery do I need?
A 25 km trip, steep terrain, sport assist, 100 kg, surface: asphalt, temperature: 0–10 °C.
- 1. Consumption9 Wh/km (steep) × 1.3 (assist) × 1.1 (weight) = 12.9 Wh/km
- 2. Energy needed25 km × 12.9 Wh/km × 1.35 (reserve) ÷ 0.85 (cold) = 511 Wh
- 3. Roundedup to 50 Wh: 550 Wh
- 4. In the cataloguefor 550 Wh we list from 467 Wh, with the 15% tolerance
Range by battery size and terrain
At normal assist, 80 kg, on asphalt, with a mid-drive, above 10 °C, with a new battery.
| Battery | Flat | Rolling | Steep |
|---|---|---|---|
| 400 Wh | 62–84 km | 49–66 km | 38–51 km |
| 500 Wh | 77–105 km | 61–82 km | 47–64 km |
| 625 Wh | 97–131 km | 76–103 km | 59–80 km |
| 750 Wh | 116–157 km | 91–123 km | 71–96 km |
| 800 Wh | 124–167 km | 97–131 km | 76–102 km |
How we calculate
An e-bike's battery stores energy in watt-hours (Wh), and the motor uses some of it for every kilometre. The range is therefore the usable capacity divided by the consumption per kilometre.
Consumption starts from the terrain. At normal assist and 80 kg, we count 5.5 Wh per km on the flat, 7 on rolling roads and 9 on long, steep climbs. That is multiplied by the assist level, your weight, the surface, a hub motor on climbs and, for an S-pedelec, the speed. The cold and the battery's age reduce the usable capacity.
Our e-bike finder works with the same numbers, so both give the same battery size for the same question.
Why real range is shorter than the factory figure
Makers mostly measure in ideal conditions: the lowest assist, a steady pace, flat roads, no wind, an average-weight rider and well-pumped tyres. There is no binding common standard, so two makers' figures are not always comparable. In everyday riding, climbs, stronger assist, wind and luggage all use more.
That is why we give a band rather than a single number: the same battery goes noticeably different distances in another bike with another rider.
What matters most
- Assist level. We count 35% less in eco, 30% more in sport and 60% more in turbo than at normal assist.
- Weight. Every kilogram counts: consumption rises or falls by 5% for every 10 kg above or below 80 kg.
- Surface. Rolling resistance is 15% higher on gravel and 30% higher on trails.
- Motor. A hub motor is less efficient on climbs than a mid-drive: on rolling and steep ground we count 10% more energy.
- Temperature. Cold cells give less energy: we count 15% less capacity at 0–10 °C and 25% less below freezing.
- Battery age. Capacity falls gradually with every charge; after about 500 full charges, 73% of it is left.
- Speed. An S-pedelec, which assists up to 45 km/h, uses far more because of air drag: at 45 km/h we count 100% more than at 25 km/h.
How big a battery do you need?
Always plan a reserve: at least 30–40% on top of the trip, so an ageing battery or a detour causes no trouble. The “What battery do I need?” mode already includes this reserve (35%) and rounds the result up to 50 Wh.
This mode calculates the same as the range, only in reverse: with the same settings (terrain, assist, weight, surface, motor, temperature), and in the cold it asks for as much more battery as the cold makes unusable. It doesn't ask the battery's age: you are choosing a new one, and the reserve covers ageing.
For average use, a battery of about 500 Wh is mostly enough. Long, steep climbs, heavier loads or stronger assist need more. A needlessly big battery means a pricier, heavier bike and a narrower choice.
Making the battery last
- Store it dry, between 10 and 25 °C; keep it out of frost and strong sun.
- If you don't ride for a while, top it up every 2–3 months: the electronics drain it even when off, and a deep discharge can ruin the cells.
- Never open the battery; take it to a workshop if something is wrong.