50 Amp EV Charger Wire Size at 50, 75, and 100 Feet
A continuous 50 A, 240 V charger. The table repeats 50, 75, and 100 ft runs.
Formula SSC-2026.1
K method · SSC-2026.1
Minimum size
6 AWG · 13.3 mm²
Single conductor set
Voltage drop
3.69 V
1.54% · end 236.3 V
Power loss
184 W
I²R at the operating current
Required ampacity
62.5 A
Each conductor 65 A
Material estimate
$597.00
3 conductors + EMT
Conductor weight
22.1 lb
10.0 kg · approximate insulated weight
Circle diameters track circular mils. The drawing is a schematic, not a conduit-fill layout.
| Item | Net | Waste | Order | Unit price | Line total |
|---|---|---|---|---|---|
| copper 6 AWG · 13.3 mm² | 75 ft one way | cuts excluded | 3 conductors | USD | $458.25 |
| EMT conduit | 75 ft | — | 75 ft | USD | $138.75 |
| Material | Minimum size | mm² | Drop | End voltage | Loss |
|---|---|---|---|---|---|
| copper | 6 AWG · 13.3 mm² | 13.3 | 1.54% | 236.3 V | 184 W |
| aluminum | 4 AWG · 21.2 mm² | 21.2 | 1.59% | 236.2 V | 190 W |
| Distance | Minimum size | Drop | Percent | End voltage |
|---|---|---|---|---|
| 50 ft | 6 AWG · 13.3 mm² | 2.46 V | 1.02% | 237.5 V |
| 75 ft | 6 AWG · 13.3 mm² | 3.69 V | 1.54% | 236.3 V |
| 100 ft | 6 AWG · 13.3 mm² | 4.92 V | 2.05% | 235.1 V |
Show the deterministic formula
Single phase: Vdrop = 2 × K × I × D / cmil. Three phase: Vdrop = 1.732 × K × I × D / cmil. K is 12.9 for copper and 21.2 for aluminum. D is one-way feet.
Percent drop = Vdrop ÷ source voltage × 100. Green is 3% or less, amber is 3 to 5%, and red is over 5%. Power loss is I²R on the current-carrying conductors.
The smallest conductor that meets both the ampacity (125% when continuous) and the drop limit is selected. Ampacity does not include bundling or temperature correction.
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Project: 50 Amp EV Charger Wire Size at 50, 75, and 100 Feet
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This sheet is an estimate for ordering and layout discussion. It is not a sealed design. Confirm the quantities with a licensed local professional and the authority having jurisdiction before you buy or build.
Engineering notes
EV charging is treated as a continuous load, so ampacity is checked at 125 percent of 50 A, which is 62.5 A. Voltage drop is still calculated at 50 A. The default run is 75 ft of copper in EMT with a 3 percent limit. The distance table shows 50, 75, and 100 ft on the same load. A longer run can step the conductor up even when the breaker size stays at 50 or 60 A. Terminations must be listed for the conductor and the charger manual controls the breaker.
Code reference
NEC 210.19(A) and 215.2(A) informational notes recommend 3 percent on a branch circuit and 5 percent total with the feeder. Ampacity follows the 75°C column of Table 310.16 plus the small-conductor limits. Confirm the adopted edition.
Field questions
- Why is a 50 amp charger not always 6 AWG?
- Ampacity may allow 6 AWG copper at 75°C, but a long 240 V run can fail the 3 percent drop and step up. Read the distance table.
- Does continuous mean the drop uses 62.5 amps?
- No. The 125 percent factor is for ampacity. Voltage drop and watts lost use the 50 A operating current.
- What if the charger is 100 feet from the panel?
- Select the 100 ft row. If the percent turns amber or red, the recommended size has not met the limit you set.