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EV Range and Efficiency Calculator

Converts an electric vehicle's energy consumption between Wh/km, kWh/100 km, Wh/mile, mi/kWh and km/kWh, computes the driving range from the battery capacity and usable share, and reports the EPA MPGe equivalent (33.7 kWh per US gallon of gasoline).

When to use

You want an EV's range for a given consumption, or need to compare efficiency figures quoted in different units (European kWh/100 km, US mi/kWh or MPGe).

Do not use when: You need charging time (use ev-charging-time) or running-cost comparison with a petrol car (use fuel-vs-ev-cost); real-world consumption varies with speed, temperature and heating by ±30 % or more.

Formula

wh_per_km = efficiency_value converted (kWh/100 km × 10; Wh/mile / 1.609344; 1000 / (mi/kWh × 1.609344); 1000 / (km/kWh)); usable_energy_kwh = battery_capacity_kwh × usable_percent / 100; range_km = usable_energy_kwh × 1000 / wh_per_km; range_miles = range_km / 1.609344; kwh_per_100km = wh_per_km / 10; wh_per_mile = wh_per_km × 1.609344; mi_per_kwh = 1000 / wh_per_mile; km_per_kwh = 1000 / wh_per_km; mpge = mi_per_kwh × 33.7

Pure unit arithmetic; the EPA defines MPGe with 33.7 kWh as the energy content of one US gallon of gasoline (115,000 BTU). Official WLTP/EPA consumption figures already include charging losses, while dashboard figures usually do not.

Inputs

ParameterTypeUnitRequiredDescription
battery_capacity_kwhnumberkWhyesBattery capacity in kilowatt-hours (usable capacity if known; otherwise use usable_percent). Range: > 0, ≤ 1000
efficiency_valuenumberyesEnergy consumption or efficiency figure in the unit given by efficiency_unit (e.g. 160 Wh/km, 16 kWh/100 km, 3.9 mi/kWh). Range: > 0, ≤ 100000
efficiency_unitenum: wh_per_km | kwh_per_100km | wh_per_mile | mi_per_kwh | km_per_kwhyesUnit of efficiency_value.
usable_percentnumber%default 100Share of the battery available for driving (e.g. 90–95 % when the nominal capacity includes a buffer, or 60 for a 20–80 % daily window). Range: ≥ 1, ≤ 100

Outputs

OutputTypeUnitDescription
usable_energy_kwhnumberkWhbattery_capacity_kwh × usable_percent / 100.
range_kmnumberkmUsable energy / consumption.
range_milesnumbermirange_km / 1.609344.
wh_per_kmnumberWh/kmConsumption converted to watt-hours per kilometre.
kwh_per_100kmnumberkWh/100 kmwh_per_km / 10.
wh_per_milenumberWh/miwh_per_km × 1.609344.
mi_per_kwhnumbermi/kWh1000 / wh_per_mile.
km_per_kwhnumberkm/kWh1000 / wh_per_km.
mpgenumberMPGemi_per_kwh × 33.7 (EPA miles per gallon gasoline-equivalent).

Example

75 kWh at 160 Wh/km: {"battery_capacity_kwh":75,"efficiency_value":160,"efficiency_unit":"wh_per_km"} → {"range_km":468.8,"range_miles":291.3,"kwh_per_100km":16,"wh_per_mile":257.5,"mi_per_kwh":3.884,"km_per_kwh":6.25,"mpge":130.9}

60 kWh at 4 mi/kWh, 90 % usable: {"battery_capacity_kwh":60,"efficiency_value":4,"efficiency_unit":"mi_per_kwh","usable_percent":90} → {"usable_energy_kwh":54,"range_miles":216,"range_km":347.6,"wh_per_km":155.3,"kwh_per_100km":15.53,"mpge":134.8}

GET https://tttkmbb.com/api/v1/calculate/ev-range-efficiency?battery_capacity_kwh=75&efficiency_value=160&efficiency_unit=wh_per_km

Machine access

Sources

FAQ

What is MPGe?

Miles per gallon gasoline-equivalent: the miles an EV travels on 33.7 kWh, the energy in one US gallon of gasoline. It compares energy efficiency, not cost or emissions.

Why is my real range lower than this?

Rated consumption comes from standard test cycles; motorway speed, cold weather, cabin heating and roof loads raise consumption by 20–50 %, and most drivers keep a 10–20 % reserve.

Is battery capacity gross or net?

Manufacturers quote gross (nominal) or net (usable) capacity. Enter the usable value with usable_percent = 100, or the gross value with the usable share (typically 90–96 %).

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