EV Charging Time Calculator — How Long Will It Take?
Estimate how long an electric vehicle will take to charge between two battery percentages. See battery energy added, electricity drawn, range added, and range per charging hour using your charger, vehicle, and efficiency assumptions.
Quick answer: A 75 kWh usable battery charging from 20% to 80% at 7.4 kW and 90% efficiency takes about 6 hours 45 minutes, assuming steady power and a vehicle that accepts at least 7.4 kW.
Start with the labeled example below, choose a charger preset, or enter your own four core values. Consumption is optional and only affects range.
Battery and charging inputs
Example loaded: 75 kWh, 20–80%, 7.4 kW Level 2 AC. Edit any value.
Charging estimate
Charger levels at a glance
Example powers; actual charging is limited by both supply and vehicle
Charging type
Example supply / power
What limits speed?
US Level 1 / household
120 V AC; around 1.4–1.9 kW
Outlet, permitted current and vehicle
UK/EU household outlet
230 V AC; 2.3 kW at 10 A
Installation and portable equipment; not US Level 1 terminology
Level 2 / AC wallbox
US: 208/240 V; EU: single or three phase. Presets 3.7, 7.4, 11 and 22 kW
Available supply and onboard charger; 11/22 kW commonly require three phase in Europe
DC fast
Example connector ratings: 50, 150 and 350 kW
Vehicle charging curve, temperature and station output
kW measures power, the rate of energy transfer. kWh measures energy: 7 kW sustained for 2 hours transfers 14 kWh before losses.
Usable versus gross capacity
Usable energy excludes protected battery buffers. Use it for the dashboard charge window.
Charger rating versus vehicle acceptance
The lower limit wins. AC uses the onboard charger; DC bypasses that AC conversion stage.
Peak versus average DC power
Peak is the highest supported rate; the whole-session average is usually lower and depends on the charge window.
Formulas and charging models
E = usable kWh × (target % − start %) / 100 Steady AC time = E / [min(charger kW, AC limit kW) × efficiency] Wall energy = E / efficiency Range added = E / consumption × 100
Efficiency is a fraction: 90% = 0.90. Blank consumption leaves range out of the result. Equal start and target charge returns zero time and zero energy, including at 100%.
Generic DC: split the requested window at 80% and 90%. In each band, connector power = min(charger output, vehicle DC peak × band factor). Time is the sum of band energy / (connector power × charging efficiency). If the vehicle peak is unknown, use charger output as the peak proxy. The ideal baseline uses constant min(charger output, vehicle peak) with the same efficiency.
Your average DC power: enter average connector output over this specific window; time = E / (average × charging efficiency). No extra taper is applied. Milestones are not extrapolated from one session average.
Published vehicle time: the current presets support only the manufacturer’s complete 10–80% time with sufficient charger output. We do not invent intermediate charging curves or extrapolate that time above 80%. Capacity and vehicle limits must match the preset; reverse modes require a different method.
DC energy and cost: connector energy = E / connector-to-battery efficiency. Grid energy = connector energy / station conversion efficiency. The station’s advertised DC output already accounts for its conversion stage, so station efficiency changes grid energy and cost, not charging time. Cost uses grid energy, not stored battery energy.
Reverse calculations: fixed-time mode solves for ending charge using the selected model, up to 100%. Deadline mode solves for the minimum charger rating that meets the time, honoring vehicle limits and taper. It reports an unattainable deadline when no rating up to 1,000 kW can meet it under those assumptions.
How to get a useful estimate
Select the question and charging type. The page initially calculates a clearly labeled home-wallbox example.
Enter usable capacity and the charge window. A vehicle preset is optional; confirm its market and specification date.
Choose the available charger power. Use a preset or convert known volts and permitted amps. Check the vehicle’s separate AC and DC limits in Advanced options.
Review losses and the DC method. Use a matching measured session average where available. Treat the generic taper as an illustration of slowing power.
Add range or cost if useful. Neither is required for a charging-time result. Calculate, compare, then copy, download or create a link to the scenario.
Worked charging examples
Household outlet: 2.3 kW
Assume a 75 kWh usable battery, 20% start, 80% target, at least 2.3 kW vehicle AC acceptance and 84% supply-to-battery efficiency.
E = 75 × (80 − 20) / 100 = 45 kWh Battery power = 2.3 × 0.84 = 1.932 kW Time = 45 / 1.932 = 23.2919 hours ≈ 23 hr 18 min Wall energy = 45 / 0.84 = 53.57 kWh
Home wallbox: 7.4 kW
Use the same 75 kWh battery and 20–80% window, an 11 kW onboard limit and 90% efficiency.
E = 75 × 60 / 100 = 45 kWh Limited power = min(7.4, 11) = 7.4 kW Time = 45 / (7.4 × 0.90) = 6.7568 hours ≈ 6 hr 45 min Wall energy = 45 / 0.90 = 50 kWh At 0.30 currency units/kWh: cost = 50 × 0.30 = 15.00
DC fast session: 150 kW with generic taper
Assume 75 kWh usable, 20–80%, a 150 kW connector, a 150 kW vehicle peak, 95% connector-to-battery efficiency and the illustrative 70% below-80% factor.
E = 75 × 60 / 100 = 45 kWh Band power = min(150, 150 × 0.70) = 105 kW Time = 45 / (105 × 0.95) = 0.4511 hours ≈ 27 min Ideal baseline = 45 / (150 × 0.95) = 0.3158 hours ≈ 19 min Connector energy = 45 / 0.95 = 47.37 kWh Grid energy at 95% station efficiency = 47.37 / 0.95 = 49.86 kWh
Extending this generic session to 100% adds two 7.5 kWh bands: 7.5 / (150 × 0.40 × 0.95) + 7.5 / (150 × 0.20 × 0.95) = 0.3947 hours. Total = 0.8459 hours, about 51 minutes. These are illustrative results, not a specific vehicle prediction.
EV charging time FAQs
How is EV charging time calculated?
For steady AC, time = usable capacity × (target − start) / 100 / (limited power × efficiency). Efficiency is expressed as a decimal. The DC generic model adds the time for each charge band; a published vehicle time applies only to its stated window.
How long does an EV take to charge at home?
It depends on the energy needed, available power and onboard charger. For a 75 kWh battery going from 20% to 80%, a 2.3 kW outlet at 84% efficiency takes about 23 hr 18 min; a 7.4 kW wallbox at 90% takes about 6 hr 45 min. A smaller daily top-up takes less time.
How long does 7 kW or 11 kW charging take?
Adding 45 kWh at 90% efficiency takes about 7 hr 9 min at 7 kW or 4 hr 33 min at 11 kW, provided the vehicle and supply accept that power. An 11 kW station will not give this improvement if the vehicle is limited to 7 kW AC.
How much charge can I add overnight?
At a steady 7.4 kW and 90% efficiency, eight hours adds up to 53.28 kWh. In a 75 kWh usable battery that is 71.04 percentage points: starting at 20% gives about 91% ending charge. The fixed-time mode stops counting energy when the battery reaches 100%.
How many miles are added per charging hour?
Divide battery power by consumption and multiply by 100. At 7.4 kW, 90% efficiency and 28 kWh/100 miles, the estimate is 7.4 × 0.90 / 28 × 100 = 23.8 miles per active charging hour. Speed, weather and heating can change actual range.
Can a regular outlet charge an EV?
Often yes, with vehicle-compatible charging equipment and a suitable electrical installation. A US 120 V outlet may supply roughly 1.4 kW at 12 A; a 230 V outlet at 10 A supplies about 2.3 kW. These are example powers, not permission to use a particular outlet or current. Follow the equipment instructions and have the installation assessed when needed.
How do volts and amps convert to kW?
For single-phase AC, approximate kW = volts × amps / 1,000. For balanced three-phase AC, kW = √3 × line-to-line volts × amps / 1,000. At power factor 1, 230 V × 32 A gives 7.36 kW and three-phase 400 V × 16 A gives about 11.09 kW. Enter allowable charging current, not the breaker rating.
Why does a 150 kW charger not always deliver 150 kW?
The vehicle may have a lower DC acceptance limit, and even its peak may last only briefly. Battery temperature, state of charge, station sharing and voltage/current limits affect power. Charging commonly slows toward a full battery. Use an average for the same charge window, a supported vehicle time, or the labeled generic taper model.
Should I enter gross or usable battery capacity?
Use usable capacity when available. Dashboard percentages normally describe the available energy window; gross capacity can include protective buffers. Preset usable capacities are tied to a particular model year, battery variant and market.
What limits AC charging speed?
The electrical supply, charging equipment, cable and onboard charger can all limit AC power. The calculator uses the lower of your available charger power and vehicle AC acceptance. A 22 kW station cannot make an 11 kW onboard charger accept 22 kW.
What efficiency and taper should I use?
Use measured values for your vehicle and conditions when available. Outlet 84%, AC 90%, DC connector-to-battery 95% and DC station 95% are editable planning assumptions. Generic taper defaults of 70%, 40% and 20% are illustrative shares of vehicle peak below 80%, at 80–90% and at 90–100%; they are not a validated vehicle curve.
How is range added estimated?
Range added = battery energy added / consumption × 100. Enter battery consumption in kWh/100 miles or kWh/100 km, excluding charging losses. Consumption is optional and does not change charging time. Real range depends on speed, terrain, temperature, wind, load and climate control.
Does the cost estimate match a public fast-charger bill?
Not necessarily. Cost here is wall/grid energy multiplied by the entered electricity price. A public DC tariff may bill energy measured at the connector instead; the result separately shows connector energy. Connection, idle, time-based, subscription and tax charges are excluded.
Are my inputs stored or tracked?
The calculator runs locally and does not save inputs or add them to analytics events. Share links encode values after the URL’s # symbol, which is not sent with the page request. Anyone you send the link to can see the scenario; your browser may retain the link in history.
Limits and electrical safety
This is a planning calculator, not a live charger reading, installation design, guaranteed range or vehicle-specific curve prediction.
Percentages scale linearly with usable capacity. AC power and efficiency are constant; generic DC power is constant within each modeled band. Temperature, aging, balancing near full charge, voltage limits and shared-station power are not modeled separately.
Follow the vehicle’s recommended charge limits and the charging-equipment instructions. A modeled 100% milestone is not a recommendation to charge to 100%.
Use only approved equipment, connectors, adapters and electrical installations. Do not infer safe wiring, breaker ratings or allowable continuous current from these calculations. Installation or modification should be assessed by a qualified professional.
Methodology, sources and testing
Calculator content updated and checked: September 24, 2026. Publisher: Starlight Tools / Starlight Robotics.
Specifications are drawn from the linked manufacturer document and scoped to its market and model year. Published claims, calculated values and illustrative assumptions are labeled separately. Automated calculation and DOM checks use the reference cases below; these checks validate the implementation, not real-world charging performance. No independent vehicle or charger testing was performed for this page.
Where the defaults come from
Outlet 84% uses the DOE’s historical example of about 16% wall-to-battery loss as a planning starting point, not a measured outlet-specific value. Level 2 90%, DC connector-to-battery 95% and DC station conversion 95% are rounded illustrative choices informed by the differing loss stages described in ADAC’s measurements; they are not universal efficiencies. Replace them with data for your conditions.
The generic 70% / 40% / 20% taper factors are editorial assumptions, not numbers claimed by DOE or a manufacturer. DOE supports the qualitative slowdown at high charge levels; no authoritative universal taper curve exists. The factors are editable and the constant-power baseline is shown alongside them.