Ohm's Law Calculator
Calculate voltage, current, resistance, and power using Ohm's Law (V=IR). Enter any two values and get the others instantly. Perfect for electrical engineers, technicians, and students.
Why Use Our Ohm's Law Calculator?
Any Two Values
Enter any two known values (V, I, R, P) and automatically calculate the remaining two values
All Formulas Included
Shows which formulas are being used for calculations with step-by-step breakdown
Educational Examples
Learn with practical examples and understand real-world applications
Ohm's Law & Power Formulas
Basic Ohm's Law
Power Formulas
V = Voltage (Volts), I = Current (Amperes), R = Resistance (Ohms), P = Power (Watts)
Ohm's Law Calculator
Enter any two known values to calculate the remaining electrical quantities
Common Scenarios
High Power Examples
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Common Electrical Calculations
Real-world examples showing how Ohm's Law applies to everyday electrical circuits and components.
Household Examples
Electronic Components
Ohm's Law Applications
Circuit Design
Calculate component values
Safety Analysis
Determine safe operating limits
Power Consumption
Estimate energy usage
Voltage Drop
Analyze wire resistance effects
Fuse Selection
Choose proper protection
Battery Life
Calculate runtime estimates
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Understanding Ohm's Law
What is Ohm's Law?
Ohm's Law states that the current through a conductor between two points is directly proportional to the voltage across the two points. The law is expressed as V = I × R, where V is voltage in volts, I is current in amperes, and R is resistance in ohms. This fundamental principle was discovered by German physicist Georg Ohm in 1827.
The Ohm's Law Triangle
The Ohm's Law Triangle is a helpful memory tool. Place your finger over the value you want to find: if the remaining two values are side by side, multiply them; if one is above the other, divide the top by the bottom. For example, to find current (I), cover I and you get V÷R.
Power Calculations
Electrical Power is calculated using P = V × I. By substituting Ohm's Law, we get additional power formulas: P = I²R and P = V²/R. These relationships help determine power consumption, heat generation, and energy efficiency in electrical circuits. Understanding power calculations is essential for proper circuit design and electrical safety.
Professional Applications
Ohm's Law is used daily by electricians for troubleshooting circuits, engineers for designing systems, and technicians for component selection. It helps calculate wire sizes, fuse ratings, battery life, LED resistors, and motor specifications. Mastering these calculations is essential for anyone working with electrical systems.
Electrical Safety Notice
This calculator provides theoretical calculations based on Ohm's Law. Real-world conditions may vary due to temperature, material properties, and circuit complexity. Always follow electrical codes, use proper safety equipment, and consult licensed professionals for electrical work. High voltage and current can be dangerous or fatal.
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