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EV range with a chosen battery reserve

Estimate distance to your chosen charge reserve from net usable battery capacity and onboard driving consumption. Keep estimated range separate from guaranteed reach.

Start with your own numbers

Editable example

An example is filled in. Replace it with your own data to calculate.

Enter the presently usable battery capacity, current charge, charge you want to keep and the average driving consumption shown by your vehicle. For example: 60 kWh, 80%, 20% and 15 kWh/100 km. The 20% reserve is hypothetical, not a recommendation. Check vehicle data instead of guessing unknown inputs.

Current net usable battery capacity (kWh)Use the current net usable capacity from 100% to 0%, not the battery pack’s gross capacity or an unverified new-car rating. Enter 60 for 60 kWh. Check manufacturer or vehicle data if usable capacity is unknown.

Current charge (%)Enter the charge percentage shown by your vehicle: 80 for 80%, not 0.8. This page does not connect to the vehicle, read live battery data or access your location.

Charge you want to keep (%)Enter the charge percentage you want to keep. It cannot exceed current charge. The 20% example is not a universal reserve recommendation. Plan using navigation and charging conditions; driving to zero is not advised.

Onboard average driving consumption (kWh/100 km)Use onboard average driving consumption: enter 15 for 15 kWh/100 km, or convert 150 Wh/km to 15. Do not use wall or charger energy including charging losses, or km/kWh. Consumption must be above zero.

Results update when inputs are complete. A plan is kept only when you save it. Inputs and results are not uploaded.

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Example result

Estimated distance until your chosen reserve

240km

The answer estimates distance until your chosen reserve is reached, assuming constant driving consumption. It is not a guaranteed reachable distance. If current charge equals the reserve, zero means no additional energy is allocated, not necessarily an empty battery.

Energy allocated to this drive36 kWh

Energy you want to keep12 kWh

Charge allocated to this drive60 %

Worked steps

60 × (80 − 20) ÷ 100 ≈ 36
36 ÷ 15 × 100 ≈ 240

Available energy equals net usable capacity times (current charge minus reserve)/100. Estimated kilometers equal available kWh divided by kWh/100 km, multiplied by 100. This assumes charge percentage scales linearly with usable energy and consumption stays constant. Synthetic example: 60 kWh usable capacity, 80% current charge, a chosen 20% reserve and 15 kWh/100 km gives 36 kWh allocated to driving. The estimate is 36 / 15 × 100 = 240 km, leaving 12 kWh. A 20% reserve is an example, not a recommendation. The main answer stops at your chosen reserve; reserved energy is not included in that distance. Equal current and reserve percentages produce zero allocated distance, not necessarily an empty battery. A positive estimate below 0.001 km is shown as less than 0.001 rather than zero. Speed, weather, terrain, load, climate control, battery condition and parking use can change actual range. No live route, charger availability or fixed weather discount is applied. Use vehicle navigation and current charging conditions and keep a suitable margin. Driving consumption is battery-side energy, separate from wall or charger energy and charging losses.

Method and scope

References:ARTC: battery discharge, driving consumption and range、Tesla owner manual: remaining energy, consumption and range limitations、Australian energy department: capacity units and factors affecting range

What this tool helps you do

Compare estimated EV driving distance under different consumption and reserve assumptions. This is not a certified range, route forecast or guarantee of a safely reachable destination, and it does not advise driving until empty.

What to enter

Use current net usable battery capacity, charge percentages and onboard driving consumption in kWh/100 km. Do not mix gross pack capacity, wall energy including charging losses or km/kWh. Verify unknown vehicle data instead of relying on the example.

How it is calculated

Worked example

Synthetic example: 60 kWh usable capacity, 80% current charge, a chosen 20% reserve and 15 kWh/100 km gives 36 kWh allocated to driving. The estimate is 36 / 15 × 100 = 240 km, leaving 12 kWh. A 20% reserve is an example, not a recommendation.

Understanding the answer

The main answer stops at your chosen reserve; reserved energy is not included in that distance. Equal current and reserve percentages produce zero allocated distance, not necessarily an empty battery. A positive estimate below 0.001 km is shown as less than 0.001 rather than zero.

Scope and limitations

Speed, weather, terrain, load, climate control, battery condition and parking use can change actual range. No live route, charger availability or fixed weather discount is applied. Use vehicle navigation and current charging conditions and keep a suitable margin. Driving consumption is battery-side energy, separate from wall or charger energy and charging losses. Save your assumptions to compare scenarios. Use the related EV charging tool for charging time and cost; its charging-loss assumptions are separate from driving consumption.