Energy needed
16.4kWh
Will I Make It Home?
EV panic calculator. Enter your current battery, distance, temperature and speed. Get a real-world arrival SOC with a traffic-light verdict in 10 seconds.
60 kWh battery · 25 kWh/100mi EPA
28 %
1 %100 %
mi
65 mph
35 mph85 mph
32 °F
-20 °F110 °F
ft
Negative if mostly downhill. Leave at 0 for flat.
mph
From a weather app or just eyeball it.
🟡
MARGINAL
Arrival: 1%
You make it, but cut it close. Be conservative.
- Drop to 55 mph and arrival SOC improves to about 4%.
- Turn heat down to 1.5 kW or lower. Use seat heaters instead.
- Draft behind a truck if you can do it safely.
Real efficiency
39.2kWh/100mi
Max safe speed
55mph
What Makes This Different From Your Car's GOM
Your dash's guess-o-meter (GOM) is mostly a rolling average of recent efficiency. It does not know what the road ahead looks like. If you just spent 20 minutes on flat highway at 65 mph, it will happily predict that same efficiency for the next 40 miles, even if the next 40 are uphill into a 25 mph headwind at 5°F. This calculator runs an actual energy balance: starting energy, energy per mile at your conditions, and arrival SOC.
The Temperature Curve We Use
EVs lose energy in cold weather for three reasons: battery chemistry slows down (internal resistance increases), cabin heat is expensive (resistive heat pulls 1-5 kW, heat pumps only help above ~20°F), and viscous losses go up (cold tires, cold motor bearings, cold lubricants). Recurrent Motors tracked 10,000+ EVs across model years and found the average modern EV loses about 12% of range at 32°F, 24% at 20°F, 40% at 0°F, and around 50% at -10°F vs a 70°F baseline. Those numbers are interpolated inside this calculator.
The Speed Correction
Aerodynamic drag scales with the square of velocity, but energy-to-overcome-drag scales with the cube. That means every mph above ~50 mph costs proportionally more energy than the last. Bjorn Nyland's 90 km/h and 110 km/h tests and InsideEVs's 70 mph highway range tests consistently show a penalty of about 1.5% per mph above 50 mph. We apply that as a linear multiplier.
When To Actually Listen To This Tool
- Trust it for the direction(go / marginal / nope). It's unlikely to be wrong by a full category if your inputs are honest.
- Pad the answer. Arrive with 8-10% minimum. Unexpected detours, traffic idle time, and rolling elevation that averages flat but includes big climbs will all nibble at your margin.
- Heat pump advantage:if your EV has a heat pump and it's warmer than about 20°F, you use less cabin heat energy than this calculator assumes. Subtract about 30% from the heat penalty.
- DC fast charging changes everything. A 5-minute detour for a 10% top-up is almost always worth it vs crawling home at 45 mph.
Sources
- Recurrent Motors 2023 cold-weather range study (10,000+ EVs)
- InsideEVs 70 mph highway range tests
- Bjorn Nyland 90/110 km/h EV range tests
- SAE J1634 EV range test procedure
FAQ
Frequently asked
For 'will I make it' questions, yes. Your dash's guess-o-meter is a rolling average of recent efficiency and doesn't account for what the road ahead is actually going to be like. This calculator runs a full energy balance using temperature, speed, cabin heat, elevation, and wind. That said, pad the answer. Arrive with at least 8-10% for safety.