E-Bike Range Calculator
Estimate your electric bike's range in kilometres based on battery capacity, assist level, terrain, rider weight, and temperature. Use it before a ride to avoid running out of charge mid-route.
About this calculator
E-bike range is primarily governed by how much energy the battery stores (Wh) and how efficiently that energy moves the bike forward. The formula used here is: Range = round{batteryCapacity × terrainFactor × tempFactor × (100 / riderWeight) × (1 − assistLevel/100) × 0.15 × 10} / 10, where terrainFactor = 1.0 (flat), 0.7 (hilly), or 0.5 (mountainous); tempFactor = 1.0 above 0 °C, 0.8 below 0 °C (cold degrades lithium-ion battery capacity by ~20%). Heavier riders draw more current per kilometre, so weight appears as an inverse factor. Higher assist levels consume more battery power, reducing range. The constant 0.15 converts the normalised product into kilometres.
How to use
Suppose your e-bike has a 500 Wh battery, you set assist at 50%, terrain is hilly (factor 0.7), total rider+cargo weight is 90 kg, and temperature is 15 °C (factor 1.0). Range = round{500 × 0.7 × 1.0 × (100/90) × (1 − 50/100) × 0.15 × 10} / 10 = round{500 × 0.7 × 1.111 × 0.5 × 0.15 × 10} / 10 = round{291.4} / 10 = 291 / 10 = 29.1 km. Reducing assist to 25% would raise that figure by roughly 50%.
Frequently asked questions
How does cold weather affect electric bike battery range?
Lithium-ion batteries lose capacity in cold temperatures because lower temperatures slow the electrochemical reactions inside the cells. At around 0 °C, you can expect roughly 15–20% less range than at room temperature; below −10 °C, losses can reach 30–40%. Keeping your battery indoors overnight before a winter ride and using an insulating battery cover can partially mitigate this. Always plan for reduced range in cold conditions and charge to 100% before setting out.
What assist level gives the best balance between e-bike range and riding effort?
Mid-level assist (typically 30–50% on most systems) offers the best balance for most riders. At full (high) assist, the motor carries most of the load and range can be halved compared to eco/low mode. At no or minimal assist, range is maximised but you lose the primary benefit of an e-bike on hills. For long-distance touring, experienced e-bike riders often use eco mode on flat sections and boost to mid or high only for climbs, extending total range by 20–35% compared to riding at constant high assist.
Why does rider weight significantly change e-bike range?
The motor must overcome both rolling resistance and gravity, both of which scale directly with total system weight (rider + bike + cargo). A heavier rider requires more current draw from the battery per kilometre, especially on inclines. This is captured in the range formula as a (100 / riderWeight) factor — the heavier you are relative to 100 kg, the lower the range output. Reducing cargo weight, using a lighter bike, or choosing a larger-capacity battery are the most practical ways for heavier riders to maintain adequate range.