engineering Verified Precision Tool
Ohm's Law and Power Calculator
Calculate voltage, current, resistance, and electrical power with instant unit conversions.
Enter any two known electrical values. The remaining parameters will be calculated automatically.
Electrical Parameters Matrix
Voltage (V)12 V
Current (I)3 A
Resistance (R)4 Ω
Power (P)36 W
Mathematical Formula
V = I * R | P = V * I = I^2 * R = V^2 / R
Overview & Explanation
Ohm's Law states that electric current passing through a conductor between two points is directly proportional to voltage across the points.
How It Works
- Voltage V = Current I * Resistance R
- Power P = Voltage V * Current I = I² * R = V² / R
- Provide any two known values to compute the remaining parameters.
Practical Applications
- Designing electronic circuits and selecting resistor ratings.
- Determining circuit power consumption and thermal heat dissipation.
- Sizing electrical wires and circuit breakers for safe loads.
Worked Example: 12 Volts across 4 Ohms Resistance
Find current and power dissipated.
1
Calculate Current
I = 12 V / 4 Ω
= 3 A
2
Calculate Power
P = 12 V * 3 A
= 36 W
Frequently Asked Questions
What is Ohm's Law?
Ohm's Law defines the relationship between voltage (V), current (I), and resistance (R) as V = I * R.
How do you calculate electrical power?
Power (P) in Watts is calculated by multiplying Voltage by Current (P = V * I).
Related Calculators
mathematics
Percentage Calculator
Calculate percentages, percentage change, and percentage of a number instantly.
Use Calculator
finance
Mortgage and Loan Calculator
Calculate monthly mortgage payments, interest costs, and total repayment schedules.
Use Calculator
construction
Floor Area and Concrete Volume Calculator
Calculate floor surface area, slab perimeter, concrete volume, and estimated concrete bags.
Use Calculator