An 11 kW wallbox charges a car with a 7.4 kW onboard charger at 7.4 kW, and a 150 kW DC charger only holds 150 kW for part of the session. This calculator applies the onboard AC limit, models the DC taper above 80%, and tells you how many kilometres you actually gained.
How long does it take to charge an electric car?
On a 7.4 kW home wallbox, a 60 kWh car takes about 5 hours 20 minutes from 20% to 80%, including charging losses. On AC the car’s onboard charger caps the speed whatever the post offers; DC fast chargers are quicker but slow sharply above 80%, so the last 20% can take nearly as long as 10–80%.
The onboard charger is usually the bottleneck
On AC, your car converts mains power to DC inside the vehicle, and that onboard charger has a fixed ceiling — commonly 7.4 kW single-phase, or 11 kW where three-phase is available. Plug a 7.4 kW car into a 22 kW post and you charge at 7.4 kW. The post is not broken; the car simply cannot take more.
DC fast charging bypasses the onboard charger and feeds the pack directly, which is why 50–350 kW is possible. There the limits are the pack's own acceptance curve, its temperature and its state of charge — none of which stay constant through a session.
Why everyone charges to 80%
A DC session does not hold peak power. Cars typically accept full rate up to roughly 50–60% state of charge, then step down progressively to protect the cells, and above 80% the rate collapses to a fraction of peak. Going 10–80% might take 25 minutes; the last 20% can take nearly as long again.
The practical rule on a road trip is to arrive low and leave at 80%. Two short stops beat one long one, because you spend all your plugged-in time in the fast part of the curve. This calculator applies a taper factor above 80% so the estimate does not lie to you.
Charger tiers at a glance
Level 1 is a domestic socket: about 1.4 kW in North America and 2.3 kW on 230 V mains, adding 6–13 km of range per hour. It is fine if you drive under 50 km a day and can leave the car plugged in overnight.
Level 2 is a wallbox at 7.4–11 kW, adding roughly 35–60 km per hour and filling most cars overnight from any state of charge. DC fast charging runs 50 kW (older CCS/CHAdeMO), 150 kW (mainstream today) and 250–350 kW (newest 800 V platforms) — useful on journeys, unnecessary and slightly harder on the pack for daily use.
Range added per hour assumes 18 kWh/100 km, a realistic mixed-driving figure for a mid-size EV. DC figures are averaged over a typical 10–80% session rather than the peak rate. An efficient small car does better; anything large, cold or towing does worse.
| Tier | Power | Range per hour | Where |
|---|---|---|---|
| Level 1 (120 V) | 1.2–1.9 kW | 6–10 km | North American household socket |
| Level 1 (230 V) | 2.0–2.3 kW | 11–13 km | European household socket |
| Level 2 single phase | 7.0–7.4 kW | 35–41 km | Home and workplace wallbox |
| Level 2 three phase | 11–22 kW | 55–110 km | Public AC posts, some homes |
| DC fast | 50 kW | 240 km | Older highway chargers |
| DC rapid | 150 kW | 700 km | Mainstream road-trip charging |
| DC ultra | 250–350 kW | 1200 km+ | 800 V platforms only |
Connector standards
| Connector | Current | Region |
|---|---|---|
| Type 2 (Mennekes) | AC | Europe — also the AC half of CCS2 |
| J1772 (Type 1) | AC | North America, Japan |
| CCS1 / CCS2 | DC | North America / Europe |
| NACS | AC and DC | North America, now widely adopted |
| CHAdeMO | DC | Legacy Japanese standard |
For what to install at home and how the levels compare in practice, see the charging levels guide.
How the calculator works
On AC, the charge rate is the lower of the charger’s output and your car’s onboard charger, reduced by charging efficiency. On DC, the onboard charger is bypassed and the full rate applies up to 80%; above that, the calculator charges at 42% of the peak rate to reflect the taper. Range added is the energy that reaches the pack divided by your consumption.
The formula
// on DC, everything above 80% is charged at 0.42 × the peak rate
range added = kWhneeded ÷ consumption × 100
Related calculators
Once you know how long a charge takes, the charging cost calculator tells you what it costs on your tariff, and the EV versus petrol calculator sets that against a tank of fuel.
Questions riders actually ask
How long does it take to charge an EV at home?
On a 7.4 kW wallbox, a 60 kWh car from 20% to 80% takes about 5 hours 20 minutes including charging losses. On a Level 1 socket the same top-up takes around 17 hours at 230 V and closer to 30 hours at 120 V, which is why a wallbox is the single best EV purchase after the car.
Why did my DC session slow down halfway through?
Almost certainly the pack's charge curve tapering as state of charge rose, though a hot or very cold pack will also cut the rate. Shared cabinets are another cause: many 150 kW units split power between two bays when both are occupied.
Does charging efficiency matter at home?
Yes — AC charging is about 85–92% efficient once you count conversion losses and thermal management, so a 60 kWh top-up draws roughly 66 kWh from the meter. That gap is what makes home charging cost more than a naive kWh × price calculation suggests.
Is it bad to DC fast charge regularly?
Occasional fast charging is fine and modern packs are designed for it. Exclusive fast charging does accelerate degradation — studies on large fleets suggest a few extra percent of capacity loss over years compared with mostly AC charging. Use DC for trips, AC at home.
What does kW versus kWh mean here?
kW is the rate of flow, kWh is the amount delivered. A 50 kW charger running for 30 minutes delivers 25 kWh. Battery size is quoted in kWh; charger speed in kW. Dividing energy needed by charge rate gives time — which is the whole calculation, before losses and taper.
Can I use this for an electric motorbike or scooter?
Yes. Enter the pack size in kWh (a 1500 Wh scooter is 1.5 kWh) and the charger output in kW (a 42 V 5 A charger is 0.21 kW). Small vehicles have no DC fast charging, so choose AC and set the onboard limit at or above the charger output. For the slow taper at the top of a scooter charge, the battery charge time calculator is more accurate.
Sources
Primary and reference sources for the physics, standards and figures used on this page.
- Electric vehicle charging stationsU.S. DOE Alternative Fuels Data Center
- Charging electric vehicles at homeU.S. DOE Alternative Fuels Data Center