How Many Amps Does a Hair Dryer Use?
A 1875W hair dryer at 120V draws 15.63 amps.
Hair Dryer Amps Explained
1875W is the most common wattage rating for full-size hair dryers sold in the US, drawing 15.63 amps at 120V on high heat. That exceeds the 12A continuous-load limit of a standard 15A bathroom circuit, which is why bathroom outlets are required to be on their own 20A GFCI-protected circuit under modern NEC rules, rather than shared with bedroom lighting or outlets elsewhere in the house.
Frequently Asked Questions
How do I convert watts to amps?
For DC circuits, divide watts by volts (Amps = Watts ÷ Volts). For AC single-phase circuits, divide watts by the product of power factor and volts. For AC three-phase circuits, divide watts by the product of √3, power factor, and volts.
Why do I need power factor for AC calculations?
Power factor accounts for the phase difference between voltage and current caused by inductive loads like motors and compressors. Purely resistive loads (heaters, incandescent bulbs) have a power factor of 1.0. Motors typically run 0.8–0.95.
What breaker size do I need for a 1500W appliance at 120V?
1500W at 120V draws 12.50 amps. Per NEC Article 210.20, continuous loads must not exceed 80% of a breaker rated capacity, so a 15A breaker (12A max continuous) is not sufficient. A dedicated 20A circuit is required.
Does this calculator work for 240V appliances?
Yes. Enter your wattage and set voltage to 240V for dryers, water heaters, ranges, and EV chargers. At the same wattage, 240V circuits draw half the current of 120V circuits.
Is this calculator accurate for 3-phase industrial power?
Yes. Select the AC 3-Phase tab, enter your line voltage (commonly 208V or 480V), and choose line-to-line or line-to-neutral mode. The calculator uses the precise value of √3, not a rounded 1.732 approximation.
Can I use this to size wire gauge?
The calculator provides an AWG wire gauge recommendation based on NEC Table 310.15(B)(16) for 60°C copper conductors. Always confirm final wire and breaker sizing with a licensed electrician before installation.