What Is the Resistance and Power for 230V and 80A?

Using Ohm's Law: 230V at 80A means 2.88 ohms of resistance and 18,400 watts of power. This is useful for sizing resistors, understanding circuit behavior, and verifying that components can handle the power dissipation (18,400W in this case).

230V and 80A
2.88 Ω   |   18,400 W
Voltage (V)230 V
Current (I)80 A
Resistance (R)2.88 Ω
Power (P)18,400 W
2.88
18,400

Formulas & Step-by-Step

Resistance

R = V ÷ I

230 ÷ 80 = 2.88 Ω

Power

P = V × I

230 × 80 = 18,400 W

Verification (alternative formulas)

P = I² × R

80² × 2.88 = 6,400 × 2.88 = 18,400 W

P = V² ÷ R

230² ÷ 2.88 = 52,900 ÷ 2.88 = 18,400 W

Circuit Analysis

Heat Dissipation

This circuit dissipates 18,400 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
1.44 Ω160 A36,800 WLower R = more current
2.16 Ω106.67 A24,533.33 WLower R = more current
2.88 Ω80 A18,400 WCurrent
4.31 Ω53.33 A12,266.67 WHigher R = less current
5.75 Ω40 A9,200 WHigher R = less current

Same Resistance at Different Voltages

Holding the resistance constant at 2.88Ω, 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 2.88Ω)Power
5V1.74 A8.7 W
12V4.17 A50.09 W
24V8.35 A200.35 W
48V16.7 A801.39 W
120V41.74 A5,008.7 W
208V72.35 A15,048.35 W
230V80 A18,400 W
240V83.48 A20,034.78 W
480V166.96 A80,139.13 W

Frequently Asked Questions

R = V ÷ I = 230 ÷ 80 = 2.88 ohms.
P = V × I = 230 × 80 = 18,400 watts.
All 18,400W is dissipated as heat in a pure resistor at steady state. The 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.
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.
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.