Wire Sizing

Wire Size for Hot Tub — 50 Amp 75 Feet

Pre-calculated NEC-compliant wire size for 50 amps at 75 feet on a 240V single-phase circuit. Immediate answer below.

Recommended Wire Size

Copper

8 AWG

Voltage drop: 2.43% (5.84V)

Voltage at load: 234.2V

Controlling factor: Ampacity (NEC 310.16)

Aluminum

6 AWG

Voltage drop: 2.53% (6.06V)

Voltage at load: 233.9V

Controlling factor: Ampacity (NEC 310.16)

Based on NEC Table 310.16 (75°C column), single-phase, 240V, 3% max voltage drop, one-way distance 75 ft.

Wire Comparison Table

Wire Size	Ampacity	V-Drop (V)	V-Drop (%)	V at Load
14 AWG	15A	23.55V	9.81%	216.5V
12 AWG	20A	14.85V	6.19%	225.2V
10 AWG	30A	9.3V	3.88%	230.7V
8 AWGREC	50A	5.84V	2.43%	234.2V
6 AWG	65A	3.68V	1.53%	236.3V
4 AWG	85A	2.31V	0.96%	237.7V
3 AWG	100A	1.84V	0.77%	238.2V
2 AWG	115A	1.46V	0.61%	238.5V
1 AWG	130A	1.16V	0.48%	238.8V
1/0 AWG	150A	0.92V	0.38%	239.1V
2/0 AWG	175A	0.73V	0.3%	239.3V
3/0 AWG	200A	0.57V	0.24%	239.4V
4/0 AWG	230A	0.46V	0.19%	239.5V
250 kcmil	255A	0.39V	0.16%	239.6V
300 kcmil	285A	0.32V	0.13%	239.7V
350 kcmil	310A	0.28V	0.11%	239.7V
400 kcmil	335A	0.24V	0.1%	239.8V
500 kcmil	380A	0.19V	0.08%	239.8V

Table shows all standard AWG/kcmil sizes for 50A at 75 ft on 240V (copper). Green check = meets both ampacity and 3% voltage drop. REC = smallest compliant size.

Key Considerations

For a 50A circuit at 75 feet on 240V, both ampacity and voltage drop must be satisfied. NEC recommends keeping the total voltage drop (feeder + branch) under 5%, with no more than 3% on either segment alone.

Copper conductors at 75°C column (THHN/THWN-2) are assumed. If using 60°C terminations, derate the ampacity to the 60°C column values. Verify the temperature rating of your terminals.

Frequently Asked Questions

What size wire do I need for a 50 amp service at 75 feet?▾

For a 50A/240V circuit at 75 feet, use 8 AWG copper (2.43% drop) or 6 AWG aluminum. This keeps voltage drop within the NEC-recommended 3% limit.

Can I use aluminum wire for a 50 amp circuit?▾

Yes. Aluminum wire is a cost-effective alternative for larger circuits. For 50A at 75 feet, use 6 AWG aluminum (2.53% voltage drop). Aluminum requires AL-rated connectors and anti-oxidant compound at all terminations.

What happens if the voltage drop exceeds 3%?▾

Voltage drop above 3% reduces equipment efficiency, can cause motors to overheat, and may violate NEC 210.19(A) Informational Note No. 4. For a 50A circuit at 75 feet on 240V, exceeding 3% means the load receives less than 232.8V, which can damage sensitive electronics and shorten appliance lifespan.

Related Wire Size Calculations

50A / 100 ft

Wire Size for Hot Tub — 50 Amp 100 Feet

50A / 75 ft

What Size Wire for 50 Amp 240V 75 Feet

50A / 75 ft

Wire Size for 50 Amp EV Charger 75 Feet

50A / 50 ft

What Size Wire for 50 Amp 240V 50 Feet

50A / 100 ft

What Size Wire for 50 Amp 240V 100 Feet

Need a Custom Calculation?

Different voltage, three-phase, or custom max drop percentage? Use our interactive calculator.

Wire Size Calculator