Electric Vehicle Range Calculator turns battery capacity, state of charge, and mi/kWh into miles left, range before your reserve, charging stops, and range in cold or hot climates.
How the Electric Vehicle Range Calculator Estimates Miles
The Electric Vehicle Range Calculator works out how far your EV can drive on its current charge. It also shows the range before your arrival reserve, whether the charge covers a set distance, and how the range changes in cold or hot weather.
Enter your usable battery capacity in kWh, the battery health, the current charge and the level you plan to charge to. Then add your energy efficiency, an arrival reserve, a weather setting and the distance you need to cover.
Efficiency can be entered as mi/kWh, km/kWh, Wh/mi, Wh/km, kWh/100 mi or kWh/100 km. Distance can be miles or kilometers.
The Electric Vehicle Range Calculator Formula
Range is the energy in the battery times the distance each kWh carries you.
$$\text{Range} = \text{Capacity} \times \frac{\text{SOH}}{100} \times \frac{\text{Charge}}{100} \times \text{Efficiency} \times \left(1 – \frac{\text{Loss}}{100}\right)$$
With the defaults, a 75 kWh battery at 70% charge holds 52.5 kWh. At 3.5 mi/kWh in mild weather, that is 184 miles.
The loss term is where weather comes in. At 0%, the result is your range in mild conditions.
A common mistake is entering the gross battery size from a spec sheet. Some of that capacity is held back as a buffer, so use the usable figure when your maker lists it.
Usable Capacity and Battery Health
Battery health, or state of health (SOH), is the share of the original capacity the pack still holds. The Electric Vehicle Range Calculator multiplies your usable capacity by that percentage before anything else.
At 90% health, the same 75 kWh pack holds 67.5 kWh. At 70% charge and 3.5 mi/kWh, the range drops from 184 to about 165 miles.
Many EVs report health in a service app or a scan tool. If you don’t know yours, leave it at 100% for a new car.
Range Before Your Arrival Reserve
Driving to 0% is not a plan, so the first card subtracts the reserve you set. With a 10% reserve, the default charge covers 158 miles before you reach it.
$$\text{Usable range} = \text{Energy} \times \frac{\text{Charge} – \text{Reserve}}{\text{Charge}} \times \text{Efficiency}$$
The same card shows how far the reserve itself would go, 26.3 miles here. It also gives the total range in the other distance unit, 296 km at the defaults.
Cold and Hot Weather Range Loss
The weather presets in the Electric Vehicle Range Calculator come from AAA range tests run on a chassis dynamometer. Each EV had its climate control set to 72°F, and range was compared with testing at 75°F.
The two climate-control presets use AAA’s May 2026 results for newer EVs. The heater-off and A/C-off presets come from AAA’s 2019 report, which tested five EVs under the SAE J1634 range test procedure.
| Condition | AAA test | Range loss | Default charge becomes |
|---|---|---|---|
| 20°F, heater on | 2026 | 39% | 112 mi |
| 95°F, A/C on | 2026 | 8.5% | 168 mi |
| 20°F, heater off | 2019 | 12% | 162 mi |
| 95°F, A/C off | 2019 | 4% | 176 mi |
In 2026, heater use at 20°F cut range by 39.0%, close to the 41% measured in 2019. A/C at 95°F cost 8.5%, about half the 17% from the older test.
AAA notes the vehicle lineups differ, so the two studies are not a direct match. They still point the same way on cold weather.
The 2019 test with climate control off shows where the energy goes. Cold alone cost 12%, so most of the winter loss comes from heating the cabin.
The fourth card shows your range at this charge under three other conditions, so you can compare without changing the preset.
Reaching Your Destination
In the second card, the Electric Vehicle Range Calculator compares your usable range with the distance you enter. For 120 miles at the defaults, it shows 37.5 miles to spare, 34.29 kWh used, and 24.3% left on arrival.
If the distance is longer than your usable range, the card shows how far short you fall and how many charging stops you need. Each stop is counted as a charge from your reserve up to your Charge To level.
Try 300 miles with the defaults. You come up 142.5 miles short. Each charge from 10% to 90% adds about 210 miles, so one stop covers it.
Charging to a Target Level
The third card shows your range after charging to the Charge To level. At 90%, the default battery reaches 236 miles.
It also shows the energy to add, 15.00 kWh from 70% to 90%, and the 52.5 miles that energy buys. That is energy stored in the pack, and the charger draws a little more because some power is lost as heat while charging.
To turn that energy into a charging cost, the miles per kWh calculator works from your efficiency and electricity rate.
mi/kWh, Wh/mi and kWh/100 mi
EVs report efficiency in several units, and the Electric Vehicle Range Calculator accepts all six. It converts each one to km/kWh before the math runs, using 1.609344 km per mile.
The default 3.5 mi/kWh equals about 286 Wh/mi, 28.6 kWh/100 mi, 5.63 km/kWh or 178 Wh/km. A higher mi/kWh means better efficiency, and so does a lower Wh/mi or kWh/100 mi.
The EPA label lists kWh/100 mi. Your car’s trip screen may show mi/kWh or Wh/mi, and that figure reflects your real driving.
Limits the Tool Checks
Capacity, efficiency and distance must be greater than zero. Battery health and Charge To must be above 0% and no more than 100%.
Current charge can be 0% to 100%. The reserve and range loss can be zero but must stay below 100%, since a 100% loss would leave no range at all.
Charge To must be higher than the reserve, or the Electric Vehicle Range Calculator flags it. When the current charge is at or below the reserve, the alert turns red and shows the miles left.
Range Mistakes to Avoid
Typing the EPA range, such as 300 miles, into the efficiency field skews every result in the Electric Vehicle Range Calculator. Efficiency is distance per kWh, so divide the rated range by the usable capacity, or use the figure from your trip screen.
Mixing up Wh/mi and Wh/km changes the result by about 60%. Check the unit on your car’s screen before you enter the number.
Stacking losses by hand double counts them. Pick the one weather preset that matches the drive, or enter a single custom loss.
EV Range Questions
How far can an electric car go on a full charge?
Multiply the usable battery capacity by your efficiency. A 75 kWh pack at 3.5 mi/kWh goes about 262 miles from 100%. At 80% or 90%, the same car gives 210 or 236 miles. Set the current charge in the Electric Vehicle Range Calculator to 100% to see the full figure.
How much range does an EV lose in winter?
AAA’s May 2026 tests found that 20°F with the heater on cut range by 39.0%, close to the 41% it measured in 2019. Cold alone did much less, costing 12% with the heater off in the 2019 test. U.S. Department of Energy test data also points to cabin heating as the main cause. Preheating the car while it is plugged in saves battery for the drive.
Why is my real range lower than the EPA rating?
The EPA figure comes from a standard test cycle at mild temperatures. Highway speed, cold weather, heating, cooling, hills and cargo all raise energy use. Entering your own efficiency from recent driving, plus a weather preset, gives a closer estimate than the sticker.
Does battery health reduce EV range?
Yes, in direct proportion. A pack at 90% health holds 90% of its original energy, so range drops by the same 10%. On a 75 kWh battery at 3.5 mi/kWh, a full charge falls from about 262 to 236 miles. Enter your health figure to see the effect on today’s charge.