Miles ↔ kilometres
For range figures and trip distances.
Formula: km = miles × 1.609344 (exact, by definition). miles = km ÷ 1.609344.
| Miles | Kilometres |
|---|---|
| 50 | 80 |
| 100 | 161 |
| 150 | 241 |
| 200 | 322 |
| 250 | 402 |
| 300 | 483 |
| 350 | 563 |
| 400 | 644 |
| 500 | 805 |
| Kilometres | Miles |
|---|---|
| 100 | 62 |
| 200 | 124 |
| 300 | 186 |
| 400 | 249 |
| 500 | 311 |
| 600 | 373 |
| 700 | 435 |
Efficiency: mi/kWh, kWh/100 km, Wh/mi, MPGe
Seven ways to say the same thing. Enter whichever your source uses.
Formulas: kWh/100 km = 62.137 ÷ mi/kWh · kWh/100 mi = 100 ÷ mi/kWh · Wh/mi = 1000 ÷ mi/kWh · km/kWh = mi/kWh × 1.609344 · MPGe = mi/kWh × 33.705.
Which way is better? For mi/kWh, km/kWh and MPGe a bigger number means a more efficient car. For the “per distance” units (kWh/100 km, kWh/100 mi, Wh/mi, Wh/km) a smaller number is better. Mixing the two up is the most common mistake when comparing cars across regions.
The EPA’s MPGe and kWh/100 mi figures assume Level 2 AC charging and include losses in the cable and the on-board charger, so they are measured from the wall outlet. A number read off a car’s own trip computer usually does not include those losses, which is one reason it often looks better than the label.
| mi/kWh | kWh/100 mi | kWh/100 km | Wh/mi | Wh/km | km/kWh | MPGe |
|---|---|---|---|---|---|---|
| 2 | 50 | 31.1 | 500 | 311 | 3.22 | 67 |
| 2.5 | 40 | 24.9 | 400 | 249 | 4.02 | 84 |
| 3 | 33.3 | 20.7 | 333 | 207 | 4.83 | 101 |
| 3.5 | 28.6 | 17.8 | 286 | 178 | 5.63 | 118 |
| 4 | 25 | 15.5 | 250 | 155 | 6.44 | 135 |
| 4.5 | 22.2 | 13.8 | 222 | 138 | 7.24 | 152 |
| 5 | 20 | 12.4 | 200 | 124 | 8.05 | 169 |
| 5.5 | 18.2 | 11.3 | 182 | 113 | 8.85 | 185 |
Power & battery: kW, hp, PS, kWh
For motor ratings, charger speeds and battery size.
Formula: hp = kW ÷ 0.7457 · PS = kW ÷ 0.7355. US spec sheets quote mechanical horsepower (hp); European ones usually quote metric horsepower (PS, also written CV or ch). 1 PS is about 0.986 hp.
Battery size from amp-hours and volts
Some spec sheets list a pack as Ah and V instead of kWh.
kW is power, kWh is energy. kW is how fast energy flows, like a charger’s output or a motor’s rating. kWh is an amount, like battery size. A charger rated at 150 kW does not mean your car will take 150 kW: the car sets its own limit. To see how long a charge takes, use the Charging Time Calculator.
Tyre pressure: psi, bar, kPa
US cars are labelled in psi; European cars usually in bar or kPa.
Formula: kPa = psi × 6.894757 · bar = kPa ÷ 100 · psi = bar × 14.504.
| psi | bar | kPa |
|---|---|---|
| 28 | 1.93 | 193 |
| 30 | 2.07 | 207 |
| 32 | 2.21 | 221 |
| 35 | 2.41 | 241 |
| 36 | 2.48 | 248 |
| 38 | 2.62 | 262 |
| 40 | 2.76 | 276 |
| 42 | 2.9 | 290 |
| 45 | 3.1 | 310 |
Temperature: °F ↔ °C
Cold weather is the biggest everyday swing in EV range. Negative values work.
Formula: °C = (°F − 32) × 5 ÷ 9 · °F = °C × 9 ÷ 5 + 32.
Want to know what cold does to your range? The EV Range Calculator models temperature, speed and terrain.
| °F | °C |
|---|---|
| -4 | -20 |
| 5 | -15 |
| 14 | -10 |
| 23 | -5 |
| 32 | 0 |
| 41 | 5 |
| 50 | 10 |
| 59 | 15 |
| 68 | 20 |
| 77 | 25 |
| 86 | 30 |
| 95 | 35 |
Put the numbers to work
Once everything is in the same units, these tools do the next step.
Why 300 miles on a US sticker isn’t 483 km on a European one
Converting miles to kilometres is exact: 300 miles is 482.8 km. Comparing the ratings is a different matter, because the US and Europe test range differently.
The EPA’s own guidance says the most common approach is to apply a factor of 0.7 to its test results, range included. European WLTP figures do not carry that final adjustment, and the two procedures use different mixes of city and constant-speed driving. The result is that the same car usually shows a bigger number on a WLTP spec sheet than on an EPA window sticker.
One published example: InsideEVs lists the 40 kWh Nissan Leaf at 151 miles by EPA and 170 miles by WLTP, a gap of roughly 13% in WLTP’s favour. The size of the gap changes from model to model and year to year, so do not apply a flat multiplier to convert between them. Check the carmaker’s own figure for the market you are buying in.
Reading Thai or European listings?
Spec sheets in Thailand and across Europe quote WLTP range in kilometres and consumption in kWh/100 km. Use the converters above to put them on US terms, then see our Thailand model comparison or the Thailand ownership-cost calculator.
Frequently asked questions
How do I convert miles to kilometres?
Multiply miles by 1.609344, which is exact by definition. For example, 250 miles is 402.3 km. To go the other way, divide kilometres by 1.609344.
How do I convert mi/kWh to kWh/100 km?
Divide 62.137 by the mi/kWh figure. A car that manages 3.5 mi/kWh uses about 17.8 kWh per 100 km. The reverse works the same way: divide 62.137 by the kWh/100 km figure to get mi/kWh.
What does MPGe mean?
MPGe is miles per gallon of gasoline-equivalent. It treats one US gallon of gasoline as 33.7 kWh of energy (this converter uses 33.705), so MPGe is simply mi/kWh multiplied by about 33.7. At 3.5 mi/kWh that is roughly 118 MPGe.
Is kWh/100 mi the same as Wh/mi?
They are the same measurement at different scales: multiply kWh/100 mi by 10 to get Wh/mi. A car using 30 kWh/100 mi uses 300 Wh/mi, which is about 3.33 mi/kWh.
Is an EPA range the same as a WLTP range?
No. The EPA says the most common approach is to apply a factor of 0.7 to its test results, including range, whereas WLTP does not apply that final adjustment, so the same car usually shows a higher figure on a European spec sheet. Converting miles to kilometres is exact, but an EPA figure and a WLTP figure are not interchangeable.
How many psi is 2.5 bar?
2.5 bar is about 36.3 psi (1 bar is 14.504 psi). Always inflate to the pressure on your car's door-jamb placard or in the owner's manual, and check with cold tyres.
What is the difference between kW and kWh?
kW is power, how fast energy flows, such as a charger's output or a motor's rating. kWh is energy, an amount, such as battery size. Ignoring charging losses and the slowdown near full, a 60 kWh battery charged at a steady 30 kW takes about two hours.
Sources
- EPA: Fuel Economy and EV Range Testing (the 0.7 adjustment factor, and MPGe measured at the wall including charging losses).
- EPA: Text Version of the Electric Vehicle Label (what kWh/100 mi, MPGe and range mean on the label).
- InsideEVs: EPA vs WLTP EV range ratings (WLTP has no final adjustment; the Nissan Leaf example).
- Wikipedia: Electric car EPA fuel economy (1 gallon of gasoline = 33.7 kWh).
Unit definitions: 1 mile = 1.609344 km (exact); 1 psi = 6.894757 kPa; 1 mechanical hp = 0.745700 kW; 1 PS = 0.735499 kW. The EPA’s gasoline-equivalent figure is 33.705 kWh per US gallon (often rounded to 33.7). Updated October 2026.