The one-minute answer
CLTC, WLTP and EPA are standardized comparison procedures, not promises for a particular road, speed or weather condition.
There is no universal precise CLTC-to-WLTP or CLTC-to-EPA conversion: the gap changes by vehicle and specification.
A useful formula is usable battery energy ÷ expected consumption × 100. Insert motorway or winter consumption when that is the trip you are planning.
Calculate the fast-charging leg separately. A 10–80% window makes 70% of usable battery energy available between stops.
What CLTC, WLTP and EPA actually measure
CLTC appears in China-market specifications. GB/T 18386.1-2021 defines test methods for electric-vehicle energy consumption and range. The underlying CLTC was developed from Chinese traffic data and contains comparatively more low-speed operation, stops and speed changes — conditions in which an EV can make good use of regenerative braking.
WLTP is set out in UN Regulation No. 154 and is used for type approval across many European markets. Its main value is a repeatable comparison under one procedure. It does not promise that every driver will reproduce the number on a motorway.
EPA label estimates use prescribed city and highway testing plus adjustments intended to account for factors outside the basic laboratory cycles. The agency still describes range as a consumer guideline: speed, temperature, terrain, tyres, HVAC use and load all change the result.
Why one conversion factor creates false precision
Multiplying every 700 km CLTC claim by 0.7 or 0.8 is convenient but unreliable. Cars differ in aerodynamics, battery buffers, drivetrain efficiency, thermal systems, wheel options and the way their consumption changes between city and motorway driving. Two vehicles with the same CLTC rating can therefore show different gaps to WLTP or EPA.
Compare like with like: the same drivetrain, battery, wheel size and model year. If the exact configuration carries two official ratings, those are useful reference points. If it does not, label any estimate as an estimate rather than a certified figure.
Fun fact
A bare “700 km range” claim is incomplete without the test cycle, specification and wheel size. It may be a useful comparison number, but it is not a route plan.
The formula that is more useful than advertised range
How to calculate range for your trip
You need two inputs and an honest state-of-charge window.
- 1
Find usable battery energy
Use usable or net capacity when the manufacturer publishes it. Gross capacity includes protective buffer that is normally unavailable to the driver.
- 2
Choose realistic consumption
Match the use case: urban, mixed, motorway or winter. Your own recent average on a similar route is best; an independent test of the exact version is the next-best input.
- 3
Calculate the 100–0% figure
Formula: usable kWh ÷ kWh/100 km × 100. Example: 80 ÷ 20 × 100 = 400 km.
- 4
Apply the charging window
For 10–80%, multiply usable energy by 0.70. An 80 kWh battery then offers 56 kWh; at 20 kWh/100 km, that is about 280 km between stops.
Important: Keep a reserve for diversions, headwinds, climbs, a failed charger and changing weather. A plan should not depend on arriving at 0%.
Worked example: 80 kWh usable battery
Consumption → calculated distance
20 kWh/100 km
400 km from 100–0% · 280 km in the 10–80% window
Consumption → calculated distance
14 kWh/100 km
571 km from 100–0% · 400 km in the 10–80% window
Consumption → calculated distance
16 kWh/100 km
500 km from 100–0% · 350 km in the 10–80% window
Full matrix
18 kWh/100 km
Consumption → calculated distance
444 km from 100–0% · 311 km in the 10–80% window
22 kWh/100 km
Consumption → calculated distance
364 km from 100–0% · 255 km in the 10–80% window
24 kWh/100 km
Consumption → calculated distance
333 km from 100–0% · 233 km in the 10–80% window
26 kWh/100 km
Consumption → calculated distance
308 km from 100–0% · 215 km in the 10–80% window
28 kWh/100 km
Consumption → calculated distance
286 km from 100–0% · 200 km in the 10–80% window
Why 10–80% matters more than 100–0% on a road trip
A full-battery rating is useful for comparison, but a road-trip driver rarely runs to zero and waits for 100% at every rapid charger. Charging power on many batteries drops substantially near the top of the pack; the US Department of Energy notes that the last 20% can take disproportionately longer.
Plan with two numbers: maximum distance after a full overnight charge and the distance between deliberate charging stops. The second depends on your chosen window. Ten to 80% is a clear example, not a universal rule: a particular car, charger curve, weather forecast or safety margin may make 5–75%, 10–70% or another window quicker and safer.
Motorway speed, cold and wheels can matter more than the cycle name
Aerodynamic drag rises quickly with speed. In cold weather, energy also heats the battery and cabin, while battery performance and charging are temperature-sensitive. One controlled US Department of Energy comparison found that EV fuel economy in 20°F (about −7°C) city driving could fall by nearly 40%. That is not a universal winter deduction; it shows why the operating conditions matter.
Before a long trip, check recent consumption at a similar speed and temperature. Precondition while plugged in, set tyre pressures correctly, and add margin for headwinds and elevation. Use the AutoCore car catalogue to compare battery and powertrain versions, then keep the owner guides for practical operating questions.
Frequently asked questions
Which EV range cycle is the most realistic?+
Can I convert CLTC to WLTP exactly?+
Should I use gross or usable battery capacity?+
Why can motorway range be lower than city range?+
How should I estimate winter range?+
Why this matters when comparing Chinese EVs
Large CLTC numbers often reach listings before local test results do. A buyer who understands the cycle and can calculate distance from energy compares cars more fairly, chooses the right battery and plans charging with a sensible reserve.
Sources and standards
Editor verdict
Use CLTC, WLTP and EPA to compare vehicles within the same standard. For a purchase or a trip, calculate two personal numbers: full range from usable energy and consumption, then working range inside your chosen charging window. That is more honest than any universal converter.