Mercedes-Benz EQS 400: energy use, battery size and what it costs to charge

EPA figures for 2026, 2027 Mercedes-Benz EQS 400 (2 configurations), plus the cost to charge at home in every U.S. state at May 2026 electricity prices.

The Mercedes-Benz EQS 400 uses 42.66 kWh per 100 miles. Across the 223 electric cars on sale that figure runs from 23.1 to 66.1, which puts this one among the thirstier.

How much does it cost to charge a Mercedes-Benz EQS 400?

At the U.S. average residential price of 19.42¢ per kWh, a Mercedes-Benz EQS 400 costs about $8.29 per 100 miles, $23.27 for a full charge, and $994 a year at 12,000 miles. The same car costs $671 a year in Nevada and $2,699 in Hawaii — a 4.0× difference driven entirely by where you plug in.

Mercedes-Benz EQS 400 vs. a petrol car

A typical new gasoline midsize or large SUV returns 21 MPG. At $4.32 a gallon — the U.S. average for the week of 2026-09-14, up 14.3% on the year — that is $20.57 per 100 miles against $8.29 for the Mercedes-Benz EQS 400 on average-priced electricity. Over 12,000 miles the fuel difference is $1,474 a year in favour of the electric car.

Cost to charge a Mercedes-Benz EQS 400 in every state

Every Mercedes-Benz EQS 400 configuration compared

Questions people ask about the Mercedes-Benz EQS 400

How many kWh per 100 miles does a Mercedes-Benz EQS 400 use?

The Mercedes-Benz EQS 400 uses 42.66 kWh per 100 miles on the EPA combined cycle, which works out to 2.34 miles per kWh. Across all 2 EPA-rated configurations it ranges from 42.66 to 42.66 kWh per 100 miles.

How big is the Mercedes-Benz EQS 400 battery?

Its usable battery capacity works out to roughly 119.8 kWh. EPA does not publish battery size directly, so this is calculated from EPA range (312 miles) and rated energy use, corrected for charging losses — expect a few kWh of error against the manufacturer figure.

How much does it cost to charge a Mercedes-Benz EQS 400 at home?

About $23.27 for a full charge at the U.S. average residential electricity price of 19.42¢ per kWh, or $8.29 per 100 miles. Over a year at 12,000 miles that is $994. In Nevada the same driving costs $671; in Hawaii it costs $2,699.

How long does a Mercedes-Benz EQS 400 take to charge on a 240V charger?

EPA rates it at about 14 hours for a full charge on a 240-volt (Level 2) charger. A standard 120-volt household outlet takes roughly five to six times longer; DC fast charging is far quicker but costs considerably more per kWh than charging at home.

Is a Mercedes-Benz EQS 400 cheaper to run than a gasoline car?

On fuel alone, yes. A Mercedes-Benz EQS 400 costs about $8.29 per 100 miles in electricity. A typical new gasoline midsize or large SUV manages 21 MPG, which at $4.32 a gallon costs $20.57 per 100 miles — $12.28 more. Over 12,000 miles the difference is $1,474 a year in the EV's favour. This compares fuel only — not insurance, depreciation, maintenance or your state's EV registration fee.

Cars to compare it with

Almost identical energy use

These use within a fraction of a kWh per 100 miles of the Mercedes-Benz EQS 400, so running cost is effectively a wash between them — the decision comes down to everything else.

Other electric midsize or large SUVs

• BMW iX M60 — 42.13 kWh/100mi
• BMW iX M70 — 42.13 kWh/100mi
• Kia EV9 GT — 43.21 kWh/100mi
• Rivian R1S All-Terrain — 43.21 kWh/100mi
• Polestar 3 Pack — 41.61 kWh/100mi
• Kia EV9 GT-Line — 41.1 kWh/100mi
• Rivian R1S Quad — 44.35 kWh/100mi
• Acura ZDX Type S — 40.61 kWh/100mi
• BMW iX xDrive50 — 40.61 kWh/100mi
• Rivian R1S — 39.65 kWh/100mi

Other Mercedes-Benz electric cars

• AMG EQE — 45.55 kWh/100mi
• AMG EQS — 41.1 kWh/100mi
• CLA250 with EQ Tech — 26.75 kWh/100mi
• CLA350 with EQ Tech — 28.56 kWh/100mi
• EQB 250 — 31.5 kWh/100mi
• EQB 300 — 38.74 kWh/100mi
• EQB 350 — 38.74 kWh/100mi
• EQE 320 — 35.86 kWh/100mi
• EQE 350 — 35.11 kWh/100mi
• EQE 500 — 35.11 kWh/100mi

Where these numbers come from

Energy use per 100 miles is 3,370.5 ÷ MPGe, because EPA defines MPGe against 33.705 kWh per gasoline gallon equivalent. EPA meters that energy at the wall, so charging losses are already included.

Usable battery size is EPA range × kWh per 100 miles ÷ 100 × 0.90. The 0.90 corrects for the fact that EPA measures energy at the wall but measures range from the pack; without it the estimate runs about 10% high. It is an estimate, not a manufacturer specification — expect a few kWh of error either way.

Cost assumes home charging at the state's average residential electricity price (EIA, May 2026) and 12,000 miles a year. Public DC fast charging costs considerably more; time-of-use plans can cost less.

The petrol comparison uses the median combined MPG of current regular-gasoline, non-hybrid cars in this car's own EPA vehicle class — not an all-car average — priced at the U.S. average retail price from the EIA weekly series. It counts fuel only.