How to calculate the charging time of an electric car?

“How long does it take to charge my electric car?” That’s the question that always comes up when talking about EVs. After decades of filling up gas tanks in three minutes flat, the idea of waiting longer to charge a Renault Zoe, Tesla Model 3, or Peugeot e-208 can be confusing.But once you understand the logic behind charging times and the formula to calculate them, it all becomes clear. Whether you drive a Citroën ë-C4, a Mercedes EQA, or any other EV, this so-called “constraint” quickly becomes part of your daily routine. Let’s break down charging time and the factors that influence it, with practical tips to optimize your experience.

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The three pillars of charging time

To estimate how long your EV or plug-in hybrid will stay plugged in, three elements come into play:

Battery capacity (in kWh): This is your energy tank. A small city car like the Renault Twingo has 20–40 kWh, a family hatchback like the Peugeot e-208 ranges from 50 to 75 kWh, and premium SUVs can exceed 100 kWh. The higher the number, the longer it takes to fully charge.
Charger power (in kW): This determines how fast electricity flows into your battery. A standard home outlet delivers 2.3 kW, a reinforced outlet 3.7 kW, a home wallbox 7 or 11 kW, and highway fast chargers up to 400 kW.
Your car’s onboard charger: This regulates the flow depending on the current type. Even if you plug into a powerful charger, your car will only accept what it’s designed for. A Renault Zoe maxes out at 22 kW AC, while a Tesla Model 3 can take up to 250 kW DC.

The magic formula to calculate charging time

The math behind EV charging time fits on a sticky note:Charging time (hours) = Battery capacity (kWh) ÷ Actual power (kW)

Example: The Peugeot e-208 has a 50 kWh battery. Plugged into a 7.4 kW wallbox at home, the calculation is: 50 ÷ 7.4 = about 6.7 hours for a full charge.Simple, right?But real life is more nuanced. This formula assumes a fully empty battery (rare), constant power (never the case), and perfect conditions. In reality, expect 7 to 8 hours for our Peugeot, as charging slows down near the end and the system manages temperature. The cost depends on your electricity rate.

The wide range of charging times

Slow charging: the overnight marathon at home

Plugging into a standard 2.3 kW outlet means embracing slow charging. For a 60 kWh battery, expect 26 hours for a full charge.But no one really does that! It’s perfect for light users who top up a few kilometers each night.A reinforced outlet (3.7 kW) nearly halves the time. It requires an electrician but remains affordable. Your car quietly recharges while you sleep, and you wake up ready to go.

Accelerated charging: the modern EV standard

Home wallboxes (7–11 kW) and public AC stations (11–22 kW) are the sweet spot. In 4 to 8 hours, your battery is full.It fits our daily rhythm: plug in after work, unplug in the morning. Or plug in at the mall and leave with 100 km more range. Wallbox installation is an investment, but prices have become accessible.

Fast charging: the highway pit stop for long trips

DC fast chargers (50–400 kW) change the game. In 20–40 minutes, you get 80% of your range back.Just enough time for a coffee, restroom break, and sandwich—then back on the road for 300 km. But beware: fast charging costs more (€0.40–0.79/kWh) and stresses the battery more.Electra stands out with transparent pricing in its app and ultra-fast chargers up to 400 kW, delivering 80% in 20 minutes on compatible vehicles. Use fast charging for long trips. For daily use, your battery prefers gentler charging that preserves its lifespan.

Real-world examples: charging time comparisons

Estimated time to go from 20% to 80% battery for five EVs, based on IZI by EDF’s simulator:

Model	3.7 kW	7.4 kW	11 kW	50 kW (DC)	100 kW (DC)
Tesla Model Y	12h16	6h08	4h08	0h54	0h27
Abarth 500e	6h52	3h26	2h19	0h31	0h22 (85 kW)
Alpine A290	8h30	4h15	2h52	0h38	0h23
BMW i4 (eDrive 40)	13h16	6h38	4h28	0h58	0h30
BYD Dolphin (64.6)	9h53	4h56	3h19	0h44	0h31 (88 kW)

Tools to simplify charging time calculations

No more mental math! Dozens of apps and websites do it for you.ABRP (A Better Route Planner), Chargemap, and automaker apps factor in your exact EV model, weather, elevation, driving style…Enter your destination, and the algorithm suggests optimal stops, charging times, estimated cost, and even the right cable.Some EVs go further: Tesla preheats the battery before Supercharger stops to speed up charging. BMW, Renault, Peugeot, and Mercedes offer similar features.These smart systems save precious minutes and optimize battery health and cost.

Why does charging slow down sometimes?

Several factors affect charging speed and duration:

Charging curves aren’t linear. From 0 to 80%, power stays high. After that, it drops to to protect the battery. That’s why it’s often recommended to stop at 80% on highways: the last 20% can take as long as the first 80%!

Temperature also plays a major role. In cold weather, your EV’s battery (whether it’s a Volkswagen, Peugeot, or any other model) needs to warm up before charging. In hot weather, it needs to cool down. In both cases, part of the energy goes to thermal regulation instead of charging, which affects both speed and efficiency.

Power sharing can also impact charging time. At some stations with multiple chargers on the same electrical circuit, if four EVs plug in at once, each may only get a quarter of the total available power. This extends charging time and may increase cost if billing is based on time rather than energy consumed.

Should you always charge your EV to 100%?

Not necessarily—except for specific long trips.For daily use, keeping your battery between 20% and 80% is more than enough and helps extend its lifespan. Automakers like Renault, Peugeot, Tesla, and Volkswagen confirm this: repeated full charges accelerate cell aging and degrade battery health.Save 100% charges for the night before a long journey when you need maximum range.

Many EVs let you set a charge limit via the onboard system or mobile app. Set it to 80% for everyday use, and increase it to 100% only when needed. This feature, available on most recent models, helps preserve battery longevity. Your battery will thank you in 10 years—and so will your wallet.

Final thoughts

Calculating charging time quickly becomes second nature for EV drivers—just like estimating fuel range in a gas car. The difference? With an EV, you charge while you sleep, work, or shop. In the end, you spend less time managing your car’s energy than with a combustion engine.

The secret to a great EV experience comes down to three words: anticipation, adaptation, and peace of mind.Anticipate your energy needs, adapt your charging to your daily routine and trip type, and drive with confidence knowing that France’s charging network is expanding every day.