Enter any two known electrical values (Voltage, Current, Resistance, or Power) to automatically calculate the remaining two with step-by-step formula derivations.
Ohm's Law links the three core electrical quantities: voltage, current, and resistance. The classic Ohm's triangle arranges V on top with I and R below โ cover the quantity you want and the triangle reads off the formula: cover V to get I ร R, cover I to get V / R, and cover R to get V / I. Combining Ohm's Law with the definition of electrical power (P = V ร I) yields three more useful power formulas.
Voltage (volts) equals current (amperes) times resistance (ohms) โ the base form of Ohm's Law.
Power in watts is the rate of electrical energy transfer: voltage times current.
Power dissipated as heat by a resistance, from the square of the current โ handy when voltage is unknown.
Power from voltage and resistance alone โ useful when the current is not measured.
A 12 V battery drives 2 A through a resistor: R = V/I = 12/2 = 6 ฮฉ and P = V ร I = 12 ร 2 = 24 W. These are exactly the calculator's default inputs, so pressing Calculate reproduces the result, and the substitution steps appear in the panel beside the answer cards.
Apply the same solve-for-the-unknowns approach to two-dimensional kinematics: range, flight time, and peak height.
Browse the full physics collection — mechanics, electricity, and motion tools in one hub.
Solve PV = nRT for pressure, volume, moles, or temperature with multi-unit conversions and step-by-step work.
Browse the complete suite on the Study Calculators Hub.
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