Ohm's law.

Enter any two of voltage, current, resistance, or power. The other two auto-calculate.

// MNEMONIC

"Eagles fly over rabbits and Indians."

The Eagle (E) flies over the Rabbits (R) and Indians (I) — that's how they sit in the circles. Cover the value you want:

Ohm's Law: E = I × R

Watt's Law: P = E × I

// CALCULATOR · INPUT ANY TWO FILL ANY TWO FIELDS

// E — Voltage

// I — Current

// R — Resistance

// P — Power

// All 12

Formulas worth memorizing

E = I × R

E = P / I

E = √(P × R)

I = E / R

I = P / E

I = √(P / R)

R = E / I

R = E² / P

R = P / I²

P = E × I

P = E² / R

P = I² × R