A Tesla uses between 2 and 25 kilowatts while charging, depending on which model you own, what charger you plug into, and how full the battery already is

The kilowatt figure matters because it tells you how fast the car charges and roughly how much the electricity will cost. A Tesla Model 3 pulling 11 kilowatts from a home charger will take about 8 to 10 hours to go from empty to full. The same car at a Supercharger pulling 170 kilowatts will reach 80 percent charge in roughly 25 minutes. The difference is not just speed — it is also what kind of outlet you need and what you will pay per mile of driving.

The kilowatt number also varies mid-charge. When a battery is very low, the charger pushes power in faster. As the battery fills up, the charger automatically slows down to protect the battery's long-term health. This is why the last 20 percent of charge takes much longer than the first 20 percent.

Key Takeaways

  • Home chargers (Level 2) typically deliver 7 to 11 kilowatts and take 8 to 12 hours to fully charge a Tesla, depending on the model.
  • Superchargers deliver 170 to 250 kilowatts and can add 200 miles of range in 20 to 30 minutes, but only up to 80 percent charge.
  • A standard 120-volt household outlet (Level 1) delivers only 1.4 kilowatts and adds about 2 to 3 miles of range per hour of charging.
  • The kilowatt draw decreases as the battery fills, so charging from 10 to 50 percent is faster than charging from 50 to 100 percent.
  • Charging cost depends on your local electricity rate, not just kilowatts — a kilowatt-hour costs different amounts in different regions.

The three types of Tesla chargers and their power draw

Tesla owners encounter three charging speeds in real life: Level 1, Level 2, and DC fast charging (Supercharger). Each one draws a different amount of power from the electrical grid.

Level 1 is a standard 120-volt household outlet — the same outlet you use for a lamp or phone charger. A Tesla plugged into Level 1 draws about 1.4 kilowatts. This is the slowest option and adds roughly 2 to 3 miles of range per hour. Most owners use Level 1 only as a backup or when traveling to a place with no other charger. A Model 3 with a 75-kilowatt-hour battery would take about 30 hours to charge fully from empty on Level 1.

Level 2 is what most home installations provide. It runs on 240 volts (the same circuit as an electric dryer or oven) and draws between 7 and 11 kilowatts, depending on the charger model and the car. A Tesla Wall Connector, which is Tesla's own home charger, typically delivers 11 kilowatts. A Model 3 or Model Y will charge fully in 8 to 12 hours on Level 2. Apartments and public parking lots often have Level 2 chargers that deliver 7 kilowatts, which is slower but still practical for overnight charging.

DC fast charging (Supercharger) is what you use on road trips. Superchargers deliver between 170 and 250 kilowatts depending on the location and the car model. A newer Model 3 can accept 170 kilowatts; a Model S Plaid can accept up to 250 kilowatts. At these power levels, the battery charges very quickly at first — you can add 200 miles of range in 20 to 30 minutes — but the charger automatically reduces power as the battery approaches 80 percent. Charging from 80 to 100 percent at a Supercharger is slow and not recommended for regular use because it generates heat and stresses the battery.

Why the kilowatt number drops as you charge

When you first plug in a Tesla, the charger does not when ready deliver its maximum power. Instead, it starts lower and ramps up as the battery accepts the charge. Once the battery reaches about 50 percent, the charger begins to reduce its power output. By 80 percent, the power draw has dropped significantly. By 90 percent, it drops further still.

This slowdown is intentional. Lithium batteries degrade faster when charged at very high power when they are already mostly full. By reducing power as the battery fills, Tesla extends the battery's lifespan. This is why Supercharger networks recommend charging to 80 percent for daily use and only charging to 100 percent when you need the full range for a long trip.

On a home Level 2 charger, this effect is less noticeable because the power draw is already modest. On a Supercharger, the difference is dramatic — the first 10 percent of charge might take 2 minutes, but the last 10 percent might take 15 minutes.

How to estimate your charging cost

Kilowatts tell you power draw, but your electricity bill depends on kilowatt-hours — kilowatts multiplied by time. If your home charger delivers 11 kilowatts and you charge for 10 hours, you have used 110 kilowatt-hours of electricity.

To find your cost, multiply kilowatt-hours by your local electricity rate. Residential rates vary widely by region and season. In some states, electricity costs around 12 cents per kilowatt-hour. In others, it costs 20 cents or more. You can find your rate on your electricity bill or your utility's website.

A Model 3 with a 75-kilowatt-hour battery costs roughly $9 to $15 to charge fully at home, depending on your local rate. The same charge at a Supercharger costs more per kilowatt-hour — typically 25 to 35 cents per kilowatt-hour — but you are charging much faster, so you use it less often. For daily charging at home, Level 2 is far cheaper than Supercharging.

What size electrical service you need for home charging

If you want to install a Level 2 home charger, you need to know whether your home's electrical panel has capacity. Most homes have either 100-amp or 200-amp service. A Level 2 charger that delivers 11 kilowatts requires a 50-amp circuit, which is feasible in most homes with 200-amp service but may require an upgrade if you have 100-amp service.

An electrician can assess your panel and tell you whether you can add a charger without upgrading. If your panel is at capacity, upgrading to 200-amp service costs between $1,500 and $3,000 in most regions, though this varies by location and local electrical codes. Some utilities offer rebates for home charger installation, which can offset part of this cost.

If you rent or cannot upgrade your home's electrical service, public Level 2 chargers and Superchargers are your options. Many apartment buildings are beginning to install Level 2 chargers in parking areas, though availability is still limited in many regions.

Charging speed differences between Tesla models

Not all Teslas charge at the same rate. Older models and smaller batteries accept less power than newer models and larger batteries. A Model 3 Standard Range accepts up to 11 kilowatts on Level 2 and 170 kilowatts at a Supercharger. A Model S Long Range accepts up to 11 kilowatts on Level 2 and 200 kilowatts at a Supercharger. A Model S Plaid accepts up to 11 kilowatts on Level 2 but can accept 250 kilowatts at a Supercharger.

The battery size also matters. A Model 3 Standard Range has a 54-kilowatt-hour battery; a Model 3 Long Range has a 75-kilowatt-hour battery. The larger battery takes longer to charge fully, even at the same power level. A 54-kilowatt-hour battery on an 11-kilowatt charger takes about 5 to 6 hours. A 75-kilowatt-hour battery on the same charger takes about 7 to 8 hours.

If you are considering buying a Tesla, the charging speed at home matters more than Supercharger speed for daily use. Most owners charge overnight at home and rarely use Superchargers except on road trips. A home charger that delivers 11 kilowatts is standard and sufficient for nearly all owners.

Frequently Asked Questions

Can I charge a Tesla on a regular 120-volt outlet?

Yes, but it is very slow. A standard household outlet delivers 1.4 kilowatts and adds about 2 to 3 miles of range per hour. If you drive 30 miles a day, you would need to charge for 10 to 15 hours overnight to recover that range. Most owners use 120-volt charging only as a backup when no other charger is available.

How much does it cost to charge a Tesla at home versus a Supercharger?

Home charging costs roughly 12 to 20 cents per kilowatt-hour depending on your region, which works out to about $9 to $15 to fully charge a Model 3. Supercharging costs 25 to 35 cents per kilowatt-hour, so a full charge costs $18 to $26. Home charging is cheaper per mile, but Superchargers are faster for road trips.

Why does my Tesla charge slower the fuller it gets?

The charger automatically reduces power as the battery fills to protect long-term battery health. Charging at maximum power when the battery is already 80 percent full generates excess heat and causes faster degradation. This is why Tesla recommends charging to 80 percent for daily use.

Do I need to upgrade my home's electrical panel to install a charger?

Not always. A Level 2 charger requires a 50-amp circuit, which fits in most homes with 200-amp service. If you have 100-amp service or your panel is at capacity, you may need an upgrade costing $1,500 to $3,000. An electrician can assess your home and tell you whether an upgrade is necessary.

What is the difference between kilowatts and kilowatt-hours?

Kilowatts measure power draw at a moment in time — how much electricity the charger is pulling right now. Kilowatt-hours measure total energy used over time — kilowatts multiplied by hours. Your electricity bill charges you for kilowatt-hours, not kilowatts. A 11-kilowatt charger running for 10 hours uses 110 kilowatt-hours.