Hot Tub & Spa Breaker Size (NEC Article 680)
Free online tool • 2026 NEC Compliant
Most hardwired residential hot tubs and spas run on a dedicated 240V circuit protected by a 50 amp GFCI breaker, per NEC Article 680 Part IV. Unlike most appliance circuits, spa equipment must be GFCI-protected at the breaker itself, not just at an outlet. Check your hot tub's equipment pack nameplate for its exact amperage before sizing, then use the calculator below to confirm your breaker and wire size.
Recommended Sizing
NEC Standard SizeBreaker Type: Standard Inverse-Time
NEC Reference Note: 125% multiplier applied for continuous loads per NEC 210.20(A).
How to Use This Calculator
Check the equipment pack nameplate
Find the amperage and voltage rating on your spa's control/equipment pack — this varies by heater size and model.
Confirm GFCI breaker type
Spa circuits require a GFCI breaker per NEC 680.44, not a standard breaker.
Select wire size
Match wire to breaker: 30A = 10 AWG, 40A = 8 AWG, 50A = 6 AWG copper.
Verify disconnect placement
Locate the disconnect at least 5 feet from the spa's water edge, within sight of the equipment.
Frequently Asked Questions
What size breaker do I need for a hot tub?
Most hardwired 240V hot tubs and spas require a 50 amp double-pole GFCI breaker with 6 AWG copper wire. Smaller equipment packs may specify 40A (8 AWG copper) or 30A (10 AWG copper) — always check the nameplate on your spa's equipment pack, since amperage varies by model and heater size.
Does a hot tub breaker have to be GFCI?
Yes. NEC 680.44 requires all spa and hot tub equipment operating above 15 amps or 150 volts to ground to be protected by a GFCI breaker (not just a GFCI outlet). This applies to the branch circuit feeding the equipment pack, in addition to any GFCI-protected receptacles nearby.
How far does a hot tub disconnect need to be from the water?
NEC 680.12 and 680.22 require the readily accessible disconnecting means to be located at least 5 feet from the inside wall of the spa, while remaining within sight of the equipment.
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