Electric Bike Range Calculator
Calculate e-bike range from battery capacity, assist level, terrain, and rider weight. Enter values for instant results with step-by-step formulas.
Formula
Range (km) = Battery (Wh) / (Motor Power x Assist Factor / Speed x Terrain Factor x Weight Factor)
The range is determined by dividing total battery capacity by the adjusted power consumption per kilometer, which accounts for motor output, assist level, terrain difficulty, and rider weight.
Worked Examples
Example 1: Urban Commuter E-Bike
Problem: A commuter e-bike has a 500Wh battery, 250W motor. The rider weighs 80kg and rides on flat terrain at 25 km/h using medium assist. What is the estimated range?
Solution: Assist factor (medium) = 0.7\nTerrain factor (flat) = 1.0\nWeight factor = 1 + (80 - 75) x 0.005 = 1.025\nPower per km = (250 x 0.7) / 25 x 1.0 x 1.025 = 7.175 Wh/km\nRange = 500 / 7.175 = 69.7 km\nRide time = 69.7 / 25 = 2.8 hours
Result: Range: 69.7 km (43.3 miles) | Ride Time: 2.8 hours
Example 2: Mountain E-Bike on Hilly Terrain
Problem: An e-MTB has a 750Wh battery, 500W motor. The rider weighs 85kg on hilly terrain at 20 km/h using high assist.
Solution: Assist factor (high) = 0.9\nTerrain factor (hilly) = 1.6\nWeight factor = 1 + (85 - 75) x 0.005 = 1.05\nPower per km = (500 x 0.9) / 20 x 1.6 x 1.05 = 37.8 Wh/km\nRange = 750 / 37.8 = 19.8 km\nRide time = 19.8 / 20 = 1.0 hours
Result: Range: 19.8 km (12.3 miles) | Ride Time: 1.0 hours
Frequently Asked Questions
What factors affect electric bike range the most?
Several factors significantly impact how far an electric bike can travel on a single charge. Battery capacity measured in watt-hours is the most fundamental factor, as a larger battery stores more energy. Assist level is the next biggest factor because higher assist modes consume dramatically more power, sometimes reducing range by sixty percent or more compared to eco mode. Terrain plays a critical role since climbing hills requires substantially more energy than riding on flat ground, and even rolling terrain can reduce range by thirty percent. Rider weight affects range because heavier loads require more motor power to maintain speed. Wind resistance increases exponentially with speed, so riding at higher speeds dramatically reduces range. Temperature also matters because lithium-ion batteries perform worse in cold weather.
How is e-bike battery capacity measured and what size do I need?
E-bike battery capacity is measured in watt-hours, which represents the total energy stored. To calculate watt-hours, multiply the battery voltage by its amp-hour rating. For example, a 48-volt 13-amp-hour battery provides 624 watt-hours. For commuting under ten miles each way on mostly flat terrain, a 300 to 400 watt-hour battery is sufficient. For longer commutes of fifteen to twenty miles or hilly terrain, a 500 to 700 watt-hour battery is recommended. For extended touring or mountain riding, batteries of 700 to 1000 watt-hours provide the necessary range. Keep in mind that battery capacity degrades over time, typically losing ten to twenty percent capacity after 500 to 1000 charge cycles, so it is wise to buy slightly more capacity than your minimum requirement.
Does rider weight significantly impact electric bike range?
Yes, rider weight has a meaningful impact on e-bike range, though it is less significant than assist level or terrain. As a general rule, every additional ten kilograms of rider weight reduces range by approximately three to five percent. This impact increases on hilly terrain where the motor must work harder to lift the additional weight against gravity. A 90-kilogram rider will typically get fifteen to twenty percent less range than a 60-kilogram rider under identical conditions. Cargo weight counts too, so carrying heavy panniers or a loaded basket further reduces range. Some e-bike controllers account for weight through torque sensors that automatically adjust motor output based on pedaling force, which means heavier riders naturally trigger more motor assistance and consume more battery power.
How can I maximize my electric bike range on a single charge?
To maximize e-bike range, start by using the lowest assist level comfortable for your fitness and terrain. Maintain a moderate and steady speed rather than frequent acceleration, as consistent pace is more energy efficient. Keep tires properly inflated because underinflated tires create significantly more rolling resistance and can reduce range by ten to fifteen percent. Plan routes that minimize elevation gain when possible, choosing gradual inclines over steep hills. Pedal actively rather than relying solely on the throttle, as your human power contribution directly extends battery life. Avoid carrying unnecessary weight. In cold weather, store the battery indoors before riding and consider an insulating cover. Regular maintenance including clean and lubricated chain, properly adjusted brakes that do not drag, and correctly tensioned spokes all reduce mechanical resistance and improve efficiency.
Is my data stored or sent to a server?
No. All calculations run entirely in your browser using JavaScript. No data you enter is ever transmitted to any server or stored anywhere. Your inputs remain completely private.
Can I share or bookmark my calculation?
You can bookmark the calculator page in your browser. Many calculators also display a shareable result summary you can copy. The page URL stays the same so returning to it will bring you back to the same tool.