EV Range Calculator

Electric vehicle range is determined by battery capacity, energy consumption efficiency, speed, terrain, temperature, and driving behavior. Unlike gasoline vehicles (where MPG is relatively stable), EV range can vary by 30–50% depending on conditions.

Core range formula: Energy on board (kWh) = Battery Capacity × Current Charge % ÷ 100 Range = Energy on board ÷ Consumption × 100

That second ÷ 100 is there because consumption is entered per 100 units of distance, which is how European trip computers and window stickers quote it. Enter 15, not 0.15.

Key variables:

• Battery capacity: enter the usable figure if you know it. Most EVs hold back 5-15% at the top and bottom of the pack to protect the cells, so a battery sold as 75 kWh may only hand you 70 kWh. Manufacturers are inconsistent about which of the two they advertise.
• Consumption: in kWh/100 km or kWh/100 mi, matching the unit system you picked above. This is the running average your trip computer shows, and it moves a long way with speed, climate and heater use.
• Current charge: whatever percentage is on the dash right now.

A note on MPGe. Miles per gallon equivalent is not the same thing as miles per kWh, and treating them as interchangeable is a factor-of-33.7 mistake. The EPA (Environmental Protection Agency) defines one gallon of gasoline as 33.7 kWh of energy, so MPGe = miles per kWh × 33.7. A car managing 3.5 miles/kWh is rated around 118 MPGe.

Efficiency by cruising speed (the right-hand column is the number to type into the box below):

Temperature penalty (against a 70°F / 21°C baseline)

Pick the closest one in the weather dropdown and the calculator applies it. The right-hand column is what happens to consumption, which is the number the arithmetic actually uses. A 30% rise in consumption is a 23% drop in range, not a 30% one, and that difference catches people out.

Most of that is not the battery. It is cabin heat. An engine gives you heat for free as a waste product; an EV has to make it, and a resistive heater pulls 3 to 6 kW, which at 60 mph is like adding a whole extra passenger’s worth of drag. A car with a heat pump loses noticeably less, and preheating on the charger before you leave costs the wall rather than the pack.

Speed penalty: Aerodynamic drag increases with the square of speed. Driving 75 mph vs. 55 mph typically reduces range by 15–25%.

Worked example: A Tesla Model 3 with a 57.5 kWh usable pack, dash showing 80%, trip computer averaging 32 kWh/100 mi on the highway.

Energy on board = 57.5 × 80 ÷ 100 = 46 kWh Range = 46 ÷ 32 × 100 = 144 miles

From a full pack the same car would cover 57.5 ÷ 32 × 100 = 180 miles.

Now put that car on the same highway in February at 20°F, where consumption climbs about 30%: Effective consumption = 32 × 1.30 = 41.6 kWh/100 mi Range = 46 ÷ 41.6 × 100 = 111 miles

Nearly a quarter of the range, gone, with nothing changed but the weather. That is the single biggest thing new EV owners are unprepared for. Pick “Cold, around 20°F” in the weather box and the calculator does exactly that arithmetic for you, so both figures above come straight out of the same form.

To turn kWh into charging time or money, use the EV Charging Cost Calculator.

Real-world consumption by EV class (metric)

If you don’t know your own car’s average, these starting points work well:

Doubling the size of your battery roughly doubles range only when consumption stays constant, and it usually does not. A bigger pack is a heavier car, and a heavier car uses more energy per mile, so the second half of a big battery never quite buys what the first half did.

Manufacturer rated range: EPA, WLTP, and NEDC

Three test cycles produce three different rated ranges:

• EPA (US): Most realistic; combined city/highway with cold-and-hot adjustments. Real-world is typically 85–100% of the EPA rating.
• WLTP (Worldwide Harmonised Light Vehicles Test Procedure, Europe): Optimistic; lab tests at moderate speeds. Real-world is typically 70–85% of WLTP.
• NEDC (New European Driving Cycle, the older standard China still quotes): Most optimistic; real-world often 55–70% of NEDC.

When comparing two EVs from different markets, do the conversion: a 600 km WLTP Model Y is roughly the same as a 528 km EPA Model Y, both of which deliver about 450–500 km in mixed real-world driving.