E-Bike Range and Charging Calculator
Realistic e-bike range from battery, assist level, weight, speed, climbing and temperature — plus charge time with the lithium taper included.
Charging
Why your range never matches the brochure
- Headline figures pick flattering values for every variable at once — the lightest rider, the flattest route, the lowest assist, a mild day. All of them are achievable and nobody achieves them together.
- Climbing is the part riders underestimate. Lifting a 100 kg system a thousand metres takes roughly 270 Wh of actual work, and in turbo most of that comes out of the battery — a large fraction of a typical pack, regardless of how carefully you ride the flat sections.
- Speed costs more than it looks. Air resistance rises with the square of speed, so riding 5 km/h slower is usually worth more range than any other single change you can make.
- Cold is temporary. A freezing pack delivers noticeably less, and the capacity returns as it warms. It is not damage — but it is still a walk home if you planned around the summer figure.
How to use
- Enter your battery voltage and amp-hours — multiply them for watt-hours.
- Set the assist level you actually ride in, not the one you intend to.
- Add rider, bike and cargo together, plus the climbing on your route.
- Set the temperature, which matters more in winter than most people expect.
Frequently asked questions
Why is my real range so far below the advertised figure?
Because the advertised figure picks flattering values for every variable at once — the lightest rider, the flattest route, the lowest assist and a mild day. Each is achievable and nobody achieves all of them together. Treat any headline range as a ceiling rather than an estimate.
How much battery does climbing use?
More than riders expect, and it comes straight from physics rather than a fudge factor. Lifting a 100 kg system a thousand metres is about 270 watt-hours of actual work, and in a high assist level most of that comes from the battery — a large fraction of a typical pack, however carefully you ride the flat sections.
Does riding faster really cost that much?
Yes, because air resistance rises with the square of speed. Going from 20 to 28 km/h roughly doubles the aerodynamic part of your consumption. Riding five km/h slower is usually worth more range than any other single change available to you, including a bigger battery.
Why does cold weather cut my range?
Lithium cells deliver less usable capacity when cold — noticeably less below freezing. It is a temporary effect, not damage: the capacity comes back as the pack warms. What it is not is something to plan around with a summer figure, because that is how a winter commute becomes a walk.
Why does a full charge take so much longer than capacity divided by charger power?
Because lithium packs charge at full current to roughly 80 per cent and then taper sharply. The naive calculation is about right for the first four fifths and badly wrong for the last one, which takes nearly as long again. Charging to 80 per cent is quicker per unit of range and easier on the pack.
Does a cargo bike really use that much more?
Yes. Rolling resistance is proportional to weight and is the larger share of consumption at ordinary e-bike speeds, so a loaded cargo bike at 160 kg uses well over a quarter more energy per kilometre than a 95 kg commuter. If you carry loads, that is the number worth planning around.
When should I replace the battery?
Packs are generally considered due for replacement below about 80 per cent of original capacity, and degradation accelerates from there. Setting the health figure here shows what that actually costs you in range, which is usually more persuasive than the percentage on its own.
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