What Is the Resistance and Power for 208V and 10.4A?

208 volts and 10.4 amps gives 20 ohms resistance and 2,163.2 watts power. Ohm's Law (V = IR) and the power equation (P = VI) connect all four electrical values. Knowing any two lets you calculate the other two instantly.

208V and 10.4A
20 Ω   |   2,163.2 W
Voltage (V)208 V
Current (I)10.4 A
Resistance (R)20 Ω
Power (P)2,163.2 W
20
2,163.2

Formulas & Step-by-Step

Resistance

R = V ÷ I

208 ÷ 10.4 = 20 Ω

Power

P = V × I

208 × 10.4 = 2,163.2 W

Verification (alternative formulas)

P = I² × R

10.4² × 20 = 108.16 × 20 = 2,163.2 W

P = V² ÷ R

208² ÷ 20 = 43,264 ÷ 20 = 2,163.2 W

Circuit Analysis

Heat Dissipation

This circuit dissipates 2,163.2 watts of power as heat. In a resistor, all electrical energy at steady state converts to thermal energy. The actual component power rating needs headroom above this steady-state figure, but the specific derating depends on resistor type (carbon-comp, metal-film, wirewound each behave differently), ambient temperature, airflow or heat-sinking, and whether the load is continuous or pulsed. Check the resistor datasheet for the manufacturer-specific derating curve rather than applying a blanket margin.

If You Change the Resistance

ResistanceCurrentPowerChange
10 Ω20.8 A4,326.4 WLower R = more current
15 Ω13.87 A2,884.27 WLower R = more current
20 Ω10.4 A2,163.2 WCurrent
30 Ω6.93 A1,442.13 WHigher R = less current
40 Ω5.2 A1,081.6 WHigher R = less current

Same Resistance at Different Voltages

Holding the resistance constant at 20Ω, here is how current and power scale with source voltage. This is a reference table, not a set of separate circuit scenarios: each row is the same resistor under a different applied voltage.

VoltageCurrent (at 20Ω)Power
5V0.25 A1.25 W
12V0.6 A7.2 W
24V1.2 A28.8 W
48V2.4 A115.2 W
120V6 A720 W
208V10.4 A2,163.2 W
230V11.5 A2,645 W
240V12 A2,880 W
480V24 A11,520 W

Frequently Asked Questions

R = V ÷ I = 208 ÷ 10.4 = 20 ohms.
For purely resistive loads, yes. For reactive loads, use impedance (Z) instead of resistance (R). Z includes both resistance and reactance, and the V/I phase shift shows up in power factor.
Ohm's Law (V = IR) and the power equation (P = VI) connect all four. Given any two, you can calculate the other two.
Wire sizing for a given current is not an Ohm's Law calculation. It depends on run length, source voltage, voltage-drop target, conductor material, insulation and termination temperature rating, cable type, and ambient and bundling conditions. The dedicated wire-size calculator takes those variables as input.
P = V × I = 208 × 10.4 = 2,163.2 watts.
This calculator provides estimates for reference purposes only. Always consult a licensed electrician and verify compliance with the National Electrical Code (NEC) and local electrical codes before performing any electrical work.