How much should you charge for the range you need?
Set the range you want, your real consumption and a reserve floor. The calculator shows the charge level to aim for — and whether that's gentle on the battery or only for when you really need the range. Every value is editable.
Charge to
79%
Gentle — easy on the battery · range 20–79%
Charge ceiling zones
Calculation: 124 mi × 3.66 mi/kWh = 34 kWh needed. At 100% health you have 58 kWh, so 59 percentage points above the lower limit are needed.
Battery & units
Optional — pick your car to prefill capacity, consumption and battery health, or edit any field for a custom one.
How to read the result
The charge level is your lower-limit floor plus the energy the trip needs as a share of your usable capacity. Charging up to about 80% is easy on a lithium battery; 80–90% is fine before a longer trip; above 90% is best saved for when you truly need the range, and ideally done just before you leave. A worn battery (lower health) holds less, so it needs a higher charge level for the same range.
Frequently asked questions
- Why not just charge to 100% every time?
- Sitting at a high state of charge accelerates battery ageing. Charging only as high as a trip needs — and to 100% only just before you leave — keeps more capacity over the years.
- What is the lower limit?
- The charge you want to keep in reserve and not drive below, so you arrive with a buffer. The calculator adds the trip's needs on top of this floor.
- What if it says more than 100%?
- The trip needs more energy than the battery holds at your current health and reserve. You'll need to charge on the way, lower the reserve, or accept a shorter range.