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Guide

Electric Bike Battery Range Calculator

Electric bike battery range calculator: convert pack Wh and efficiency into ride distance using assist level, rider weight, and terrain. Plan commutes and battery upgrades with clear Wh/km math.

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Battery range starts with usable watt-hours—not the sticker on the downtube. This guide shows how to calculate electric bike range from pack capacity, discharge efficiency, and the Wh/km your route actually demands.

Benefits

  • Centers the battery: nameplate Wh × pack efficiency = energy available for the motor.
  • Links battery size to km via assist, mass, and wind/terrain multipliers on Wh/km.
  • Helps compare 400 Wh vs. 625 Wh packs on the same commute profile before you buy.

How it works

  1. Look up or estimate battery Wh (voltage × Ah, or manufacturer spec).
  2. Apply pack efficiency (88–95%) for BMS and drivetrain loss.
  3. Divide usable Wh by route Wh/km—adjusted for assist level and conditions—to get battery-backed range.

FAQ

How do I calculate electric bike range from battery Wh?

Usable Wh = pack Wh × efficiency. Range ≈ usable Wh ÷ Wh/km. A 625 Wh pack at 90% efficiency with 11 Wh/km consumption → about 51 km. Swap pack size in the calculator to see km gained from a larger battery.

How many Wh do I need for a 30 km commute?

Multiply target km by expected Wh/km, then divide by pack efficiency. At 12 Wh/km and 92% efficiency: 30 × 12 ÷ 0.92 ≈ 391 Wh minimum—add 15–25% margin for headwinds, cold, or aging cells.

Is voltage or Ah more important for range?

Range depends on total Wh (V × Ah), not voltage alone. A 48 V 13 Ah and 36 V 17 Ah pack are both about 624 Wh—similar range if efficiency and consumption match. Voltage affects sag and motor behavior, not nameplate energy.

Technical specifications

  • Battery Wh: from label (V × Ah) or OEM spec sheet.
  • Usable Wh = Wh × pack_efficiency_fraction.
  • Range_km = usable_Wh ÷ effective_Wh/km.
  • Related: ebike-battery-cycle-life, ebike-voltage-sag, ebike-charge-time.

Nameplate vs. usable Wh

Manufacturers quote gross pack energy; BMS cutoff, inverter loss, and cold weather leave less for propulsion. The efficiency field models that gap so range math reflects energy that actually turns the cranks—not the number printed on the battery housing.

Sizing the next pack

If your current pack falls short by 8 km on a regular loop, you need roughly 8 × Wh/km extra usable energy—not double the pack. Run the calculator with today’s Wh and consumption, then increase Wh until range clears your buffer—before paying for a heavier or costlier upgrade.