How WLTP EV Range Is Calculated

WLTP range comes from laboratory measurements of battery energy and driving consumption under defined conditions. The vehicle’s configuration, the resistance reproduced by the test equipment and the battery test’s stopping point all affect the result.

The driving cycle and the wider procedure

The Worldwide harmonized Light vehicles Test Procedure (WLTP) sets the conditions for measuring a vehicle’s consumption and range. Its driving cycle, the Worldwide harmonized Light vehicles Test Cycle (WLTC), specifies how speed changes second by second. This prescribed speed over time is called the speed trace.

For a typical passenger EV tested using the European four-phase Class 3b cycle, the phases are:

• low: 589 seconds;
• medium: 433 seconds;
• high: 455 seconds;
• extra-high: 323 seconds.

Together they last 1,800 seconds, cover approximately 23.27 km and reach 131.3 km/h. The mean speed including stops is about 46.5 km/h. These figures describe one cycle; determining an EV’s range also requires a battery-depletion test. UN Regulation 154: WLTP test procedures (2026 publication)

This explanation uses the normal-temperature, four-phase procedure in the 04-series text of UN Regulation 154 published in June 2026. The requirements for a particular vehicle approval depend on the applicable regulatory version and transitional provisions. Other market implementations can use different phase combinations, so a value described as WLTC in Japan should not automatically be treated as equivalent to European combined WLTP range.

Step 1: define the certified vehicle

An EV can have several wheel sizes, tyres and equipment combinations. WLTP uses vehicle families and, where permitted, interpolation to establish values for these configurations without testing every possible build.

Vehicle H represents the higher cycle-energy-demand configuration within an interpolation family; Vehicle L represents the lower-demand configuration. Their test results provide the boundaries for calculating values for eligible configurations between them.

The procedure establishes test mass from the vehicle’s mass in running order and regulated load elements. Differences in wheels, tyres and equipment also affect the resistance the vehicle must overcome. This is why two versions with the same battery and motors can have different WLTP ranges: wheels can change rolling resistance and airflow, while added equipment can increase mass.

The certified result belongs to a defined configuration. UN Regulation 154: WLTP test procedures (2026 publication)

Step 2: reproduce road resistance in the laboratory

The speed trace tells the driver how fast to drive. A separate measurement establishes the force needed to overcome resistance on the road, known as road load.

A common method is a coastdown test. The warmed vehicle decelerates in neutral or a dedicated coastdown mode while speed and elapsed time are recorded. Its preparation includes the applicable mass, tyres, pressures, alignment and aerodynamic configuration. Runs in opposite directions and corrections for environmental conditions account for effects such as wind, gradient and temperature.

The resulting road-load curve is commonly represented as:

F(v) = f0 + f1 × v + f2 × v²

Here, F is resistance force in newtons and v is speed in km/h. The coefficients are fitted to the vehicle’s measured resistance; they are not separate measurements of individual losses. The lower-order terms contain much of the rolling and mechanical resistance, while the quadratic term is dominated by aerodynamic drag.

On a chassis dynamometer, the vehicle stays in place while its wheels turn rollers. The tyres and equipment already create some resistance, so the dynamometer supplies the additional load needed to match the road target. A dynamometer coastdown checks the complete setting. A fan provides cooling airflow; the calibrated aerodynamic resistance is reproduced through the rollers. UN Regulation 154: WLTP test procedures (2026 publication)

Step 3: prepare the battery and test conditions

The battery is first discharged using the manufacturer’s recommended procedure, then given a normal full charge during a soak. The car is held for 6–36 hours in an area with a 23°C set point to establish controlled starting conditions. The test cell also uses a 23°C set point, with defined tolerances.

Rules also govern the selected driving mode and auxiliary equipment. The test therefore measures consumption under repeatable laboratory conditions, rather than reproducing the heating, cooling and other loads of a particular journey. UN Regulation 154: WLTP test procedures (2026 publication)

Electric range at low temperature is assessed separately. Annex B10 of UN Regulation 154 specifies a −7°C set point for the soak and test. It establishes a declared ratio of low-temperature to normal-temperature range for a low-temperature vehicle family. That ratio is applied to an individual vehicle’s normal-temperature range to determine its low-temperature result. UN Regulation 154: WLTP test procedures (2026 publication)

EU rules adopted in July 2026 include this test in Euro 7 approval for pure electric vehicles. For the standard full Euro 7 route covering passenger cars and light vans (M1 and N1), the listed application dates are 29 November 2026 for new types and 29 November 2027 for new vehicles. The transitional Euro 7-TEMP route lists the cold-range requirement as not applicable and permits registration through 28 November 2027; small-volume manufacturers have separate dates. The low-temperature result is separate from the normal-temperature combined range. EU Regulation 2026/1764: electric range at low temperature

Step 4: deplete the battery

WLTP provides a consecutive-cycle test and a shortened test procedure for battery-electric vehicles. With the four-phase cycle, an estimated range shorter than three cycles requires the consecutive-cycle test; at three cycles or more, approximately 70 km, the shortened procedure applies. Within an interpolation family, Vehicle H’s estimated range determines the method. UN Regulation 154: WLTP test procedures (2026 publication)

In the consecutive-cycle route, the vehicle repeats the applicable driving sequence until it reaches the prescribed stopping criterion.

The shortened procedure reduces laboratory time by using constant-speed driving between measured dynamic segments. For the four-phase procedure described here, its sequence is:

1. Start with the fully charged, soaked vehicle.
2. Drive the first dynamic segment: a complete low, medium, high and extra-high cycle, followed by a city cycle comprising low and medium phases.
3. Drive the middle constant-speed segment to deplete the battery more quickly.
4. Drive the second dynamic segment, again consisting of the complete cycle followed by the city cycle.
5. Drive the final constant-speed segment until the stopping criterion is reached.
6. Recharge the battery and measure the energy supplied.

The two constant-speed segments use the same speed. Their minimum is 100 km/h for the four-phase procedure. Where the extra-high phase is excluded, the specified minimum is 80 km/h; if the vehicle cannot reach the required minimum, its maximum speed is used. A higher constant speed requires approval. UN Regulation 154: WLTP test procedures (2026 publication)

The dynamic segments establish cycle consumption at different battery charge levels. Energy measured across the full depletion test establishes the usable battery energy. The constant-speed distance is therefore not added directly to the reported combined WLTP range.

When does the test stop?

Displayed 0% is not the stopping criterion. In the shortened procedure, the test ends when the vehicle exceeds the prescribed speed-trace tolerance for four consecutive seconds or more during the final constant-speed segment. The accelerator control is then deactivated, and the vehicle is brought to a standstill within 60 seconds. UN Regulation 154: WLTP test procedures (2026 publication)

If the dashboard reaches 0% before that endpoint, energy delivered afterwards remains part of the measured test. Conversely, a vehicle that can no longer maintain the required speed may still be able to supply energy at a lower load. The endpoint establishes usable energy under the test conditions, rather than every watt-hour that could be extracted under other conditions.

Step 5: distinguish battery energy from recharge energy

Throughout depletion, the test records battery-terminal voltage and current. Integrating their product over time gives the net electrical energy delivered by the battery:

Battery energy delivered = integral of battery voltage × battery current over time

In this expression, discharge is positive and energy returned during regeneration is negative. The measured quantity covers the interval from the prescribed full-charge condition to the test’s stopping criterion. UN Regulation 154: WLTP test procedures (2026 publication)

This test-defined usable energy need not equal either advertised gross capacity or energy between displayed 100% and 0%. EVKX defines net capacity as all driver-accessible energy until propulsion stops, including any accessible reserve below displayed zero. In the shortened procedure, the test can end while the car can still propel itself at a lower speed, because it can no longer maintain the required constant speed. For the distinction between that reserve and inaccessible protective margins, see Battery buffer and usable capacity.

After depletion, the procedure requires the vehicle to be connected to the mains within 120 minutes. Equipment between the mains and the vehicle charger measures the electricity supplied during the prescribed recharge. That AC measurement supports charging-inclusive consumption reporting, while battery-side DC measurements support the range calculation. UN Regulation 154: WLTP test procedures (2026 publication)

At the test-result level, WLTP calculates recharge-based consumption by dividing mains recharge energy by range. With matching, unrounded values and consumption in kWh/100 km, the reverse calculation is:

Recharge energy (kWh) = range (km) × recharge-based consumption (kWh/100 km) ÷ 100

The product represents mains recharge energy, not usable battery capacity. Published figures may not reproduce the exact measured energy because of rounding, declaration rules or differences in configuration. UN Regulation 154: WLTP test procedures (2026 publication) Charging Loss explains how the measurement point changes the energy included.

Step 6: calculate consumption and range

The shortened procedure combines consumption measured during the dynamic segments using regulated weighting. For consumption expressed in kWh/100 km, the simplified relationship is:

Range (km) = test-defined usable battery energy (kWh) ÷ weighted battery-side consumption (kWh/100 km) × 100

For an illustrative 75 kWh of measured usable energy and weighted consumption of 15 kWh/100 km:

75 ÷ 15 × 100 = 500 km

Both inputs are battery-side quantities from the relevant test. The official calculation also applies the prescribed phase weighting, corrections and declaration rules; the example shows the underlying energy relationship. UN Regulation 154: WLTP test procedures (2026 publication)

Combined range uses the full applicable cycle. City range uses the low and medium phases, which have a different energy demand. A city figure and a combined figure therefore describe different driving profiles.

Using the result to compare vehicles

A four-phase cycle includes stops and low-speed driving as well as its extra-high phase. Reaching 131.3 km/h briefly does not make its result equivalent to sustained motorway driving. The normal-temperature result also does not reproduce the heating demand and battery conditions of a winter journey.

For a comparison, check:

• the market implementation and applicable test procedure;
• whether both figures are combined or both are city values;
• the relevant wheel, tyre and powertrain configuration;
• whether the figures are certified or provisional;
• whether any consumption figures use battery-side energy or include recharging.

There is no universal percentage deduction that converts WLTP range into motorway or winter range. For a journey estimate, use consumption and available battery energy suited to the intended conditions. Understanding EV Range shows how to make that calculation.