What Size Breaker for Hot Tub / Spa?
A hot tub / spa requires a 50A breaker with 6 AWG wire on a 240V dedicated gfci circuit. This is a continuous load — breaker rated at 125% of actual draw.
🔌 Wire Length & Voltage Drop Check
Hot Tub / Spa Wiring Guide — NEC Requirements
Hot tubs require a dedicated 240V GFCI-protected circuit per NEC 680.44. Most hot tubs draw 30-50A. A GFCI breaker is mandatory — this cannot be substituted with a GFCI outlet.
Pro Tip
💡 The disconnect must be within sight of the hot tub and at least 5 feet away per NEC 680.12.
Why a 50A Breaker?
The hot tub / spa draws approximately 40A at 240V (9600W). As a continuous load (3+ hours), NEC 210.20 requires the breaker at 125%: 40A × 1.25 = 50.0A → 50A breaker.
Wire Sizing per NEC 310.16
For a 50A/240V circuit, 6 AWG copper is required per NEC Table 310.16 at 75°C. For runs over 75 feet, upsize to 4 AWG (long runs). Use our Wire Size Calculator and Voltage Drop Calculator.
Complete Parts List
To wire a hot tub / spa circuit: a 50A double-pole breaker, 6 AWG NM-B cable (Romex) for interior runs or THHN/THWN-2 in conduit for exposed runs, a NEMA 14-50 receptacle (or hardwired), cable clamps, and appropriate junction boxes.
Disclaimer: This guide is for reference only. All electrical work must be performed by or verified by a licensed electrician. Local codes may differ from NEC.