Method and source check
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Editorial check of method and sources; this is not professional review or advice.
Method
Provide exactly two of voltage, current, and resistance. The calculator rearranges Ohm's law to find the third value, then calculates electrical power.
V = I × R
I = V / R
R = V / I
P = V × I
Variables and units
- V
- voltage in volts
- I
- current in amperes
- R / P
- resistance in ohms / power in watts
Worked example
With 12 V and 6 Ω, current is 12 / 6 = 2 A and power is 12 × 2 = 24 W.
Limitations
Voltage, current, resistance, and power are each rounded to at most three decimal places and displayed without trailing zero padding.
- This models an ideal resistive DC circuit. It does not account for AC impedance, component tolerances, temperature effects, or electrical safety requirements.
- Input 12 V and 6 Ω returns 2 A and 24 W.
- Input 2 A and 6 Ω returns 12 V and 24 W; input 12 V and 2 A returns 6 Ω and 24 W.
- Exactly two values are required. Input 12 V with 0 A fails validation because resistance would require division by zero; 0 V with 6 Ω is accepted and returns 0 A and 0 W.