NEDC ↔ WLTP Conversion Tool
Use this estimator to convert published figures between NEDC and WLTP test cycles. It works for EV range, fuel consumption, and CO₂ values using common approximation factors.
What this NEDC vs WLTP calculator does
Car listings and brochures often mix test standards. One model may show an old NEDC number, while another shows a newer WLTP number. If you compare them directly, you can easily pick the wrong “better” vehicle. This calculator helps you estimate apples-to-apples values quickly.
It is designed for practical comparison, not certification. Manufacturers and regulators use tightly controlled lab procedures, and every model behaves differently. Still, for rough shopping decisions, a transparent conversion estimate is better than guessing.
NEDC vs WLTP in plain English
NEDC (New European Driving Cycle)
NEDC is the older European test cycle. It generally produced optimistic results because it used gentler speeds, slower accelerations, and test conditions that did not reflect many modern driving patterns. For EVs, this often meant longer official range figures than drivers could realistically expect.
WLTP (Worldwide Harmonised Light Vehicle Test Procedure)
WLTP is the newer and more realistic test method. It uses a broader speed profile, stronger accelerations, and test assumptions that better reflect real-world driving behavior. Compared with NEDC:
- EV range numbers are usually lower (more conservative).
- Fuel consumption values are usually higher.
- CO₂ values are usually higher.
Default conversion factors used in this calculator
- Range: NEDC → WLTP uses 0.78 (about 22% lower).
- Consumption: NEDC → WLTP uses 1.20 (about 20% higher).
- CO₂: NEDC → WLTP uses 1.20 (about 20% higher).
Reverse conversions use the inverse of each factor. You can override with a custom factor if you have brand-specific data.
How to use the calculator correctly
- Select your metric type (Range, Consumption, or CO₂).
- Choose whether your number starts in NEDC or WLTP.
- Enter your value and optional unit label.
- Click Calculate to get an estimated converted value.
If you are comparing multiple vehicles, keep the same unit system across all of them (for example, all in km and kWh/100km).
Worked examples
Example 1: EV range
A used EV listing claims 520 km NEDC. Estimated WLTP:
520 × 0.78 = 405.6 km WLTP
This is often much closer to what buyers expect than the original NEDC number.
Example 2: Fuel consumption
A hybrid brochure shows 4.5 L/100km NEDC. Estimated WLTP:
4.5 × 1.20 = 5.4 L/100km WLTP
Example 3: Reverse conversion
If a car is rated at 6.0 L/100km WLTP, estimated NEDC equivalent is:
6.0 ÷ 1.20 = 5.0 L/100km NEDC
Why conversions are only estimates
No single factor can perfectly convert every model. Final differences depend on:
- Vehicle mass and aerodynamics
- Powertrain type (ICE, hybrid, PHEV, BEV)
- Tire choice and wheel size
- Temperature and accessory loads (HVAC, heated seats, etc.)
- Driving style and road profile
That is why this page includes a custom factor field—advanced users can adapt the estimate with known fleet or model-specific ratios.
Quick buyer tips: EV range and consumption checks
- Use WLTP for cross-brand comparisons whenever possible.
- For daily planning, estimate real-world EV range below WLTP (often by another 10–25%, depending on climate and speed).
- At highway speed, expect energy use to rise significantly.
- If two listings use different test standards, convert first, then compare.
FAQ
Is WLTP always accurate in real life?
Not always. WLTP is better than NEDC for realism, but your real result still depends on temperature, speed, terrain, and driver behavior.
Can I use this for miles instead of kilometers?
Yes. Because the conversion is a ratio, it works in either km or miles as long as input and output use the same unit.
Should I trust one exact decimal place?
No. Treat conversion results as planning-grade estimates, not legal specs. Use them to compare options, not to guarantee a specific performance outcome.
Bottom line
If you're comparing cars across model years, marketplaces, or imported listings, this NEDC vs WLTP calculator can save you from misleading comparisons. Convert first, then decide—your shortlist will be much more realistic.