EV Trip Energy Calculator
Enter your trip distance, battery capacity, current charge level, and consumption — instantly see how much energy the trip needs, your total available range, and whether you can complete the trip on a single charge.
Last updated: May 2026
Enter trip distance, battery, current charge, and consumption above.
Available range = battery × current% ÷ 100 ÷ (Wh/km ÷ 1000) — arrives at ≥10% recommended buffer
How the EV trip energy calculator works
Enter four values and the calculator tells you three things: how much energy the trip needs, how far you can go on your current charge, and whether a single charge gets you there — including a 10% battery buffer as a safety margin.
Formula reference
| What you get | Formula | Example (350 km trip) |
|---|---|---|
| Energy needed | distance (km) × consumption (Wh/km) ÷ 1000 | 350 × 170 ÷ 1000 = 59.5 kWh |
| Available energy | battery (kWh) × current% ÷ 100 | 77 × 80% ÷ 100 = 61.6 kWh |
| Available range | available energy ÷ (consumption ÷ 1000) | 61.6 ÷ 0.170 = 362 km |
| Range with 10% buffer | (battery × (current% − 10)%) ÷ (consumption ÷ 1000) | (77 × 70%) ÷ 0.170 = 317 km |
Why the 10% buffer matters
- Most EVs show reduced performance and heating below 10–15% state of charge
- Arriving at a charger on 0% risks being stranded if the charger is busy or faulty
- Cold weather can reduce usable range by 20–30% — the buffer provides a safety margin
- The calculator flags when the trip is within range including the buffer (no charge stop needed), within raw range but cuts into the buffer, or requires at least one charge stop
Frequently Asked Questions
Can I complete my trip without a charge stop?
The calculator tells you directly. If your available range (including the 10% buffer) exceeds the trip distance, you can complete it without stopping. If it falls short, you will need at least one charge stop — use the EV Charging Time Calculator to plan how long to charge mid-route.
Why does my real range differ from the calculated range?
The calculator uses a fixed consumption figure. Real-world range varies with speed (motorway driving at 130 km/h uses significantly more than city driving), temperature (cold weather reduces range by 20–30%), payload, tyre pressure, and terrain. For highway trips, use 200–230 Wh/km rather than the city consumption figure.
What consumption figure should I use for a motorway trip?
For a motorway trip at 110–130 km/h, use 190–240 Wh/km depending on the vehicle. The quick-value "220 motorway" is a reasonable starting point for most family EVs. In cold weather (below 5°C) increase by a further 15–25%. Your car's trip computer efficiency screen after a recent motorway drive gives the most accurate figure.
Does this account for charging stops along the way?
No — this calculator answers one question: does your current charge get you there? It does not route or plan multi-stop charging. If the result shows a charge stop is needed, plan the stop location using a tool like ABRP (A Better Route Planner) or your car's built-in navigation, then use the EV Charging Time Calculator to estimate the stop duration.