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Current calculator
Current calculatorCurrent
Ohm's Law Β· I = V/R Β· Full Circuit Analysis
Ohm's Law: V = I Γ R | Power: P = V Γ I = IΒ²R = VΒ²/R
About the Current calculator
Use Ohm's law to find current, voltage, resistance or power in a simple electrical circuit.
How to use the Current calculator
- Choose what to solve for under Solve For (I, V, R or P).
- Enter the known values such as Voltage (V) and Resistance (Ξ©).
- Press Calculate.
Formula and method
I = V Γ· R, V = I Γ R, R = V Γ· I and P = V Γ I.
Worked example
A 12 V supply across a 4 Ξ© resistor drives 3 A and dissipates 36 W.
Tips
- Current is measured in amperes, resistance in ohms and power in watts.
- Check that a component can handle the power it will dissipate.
Frequently Asked Questions
Even small currents through the body can be dangerous. Never work on live mains circuits unless qualified.