Resistance Calculator

Calculate Resistance, Voltage, Current, and Power

Use this calculator to determine any of the four variables in Ohm's Law: resistance, voltage, current, or power. Enter any two known values to calculate the other two.

How to Use the Resistance Calculator

The Resistance Calculator is a versatile tool based on Ohm's Law, which describes the fundamental relationship between voltage, current, and resistance in electrical circuits. This calculator allows you to determine any of these values, as well as power, when you know at least two of the other values.

Ohm's Law Formulas

The basic formulas of Ohm's Law are:

\[V = I \times R\] \[I = \frac{V}{R}\] \[R = \frac{V}{I}\] \[P = V \times I\]

Where:

  • V is voltage in volts (V)
  • I is current in amperes (A)
  • R is resistance in ohms (Ω)
  • P is power in watts (W)

How to Use the Calculator

  1. Identify at least two known values in your circuit (voltage, current, resistance, or power)
  2. Enter these values into the corresponding fields in the calculator
  3. Leave the fields for unknown values blank
  4. Click the "Calculate" button
  5. The calculator will determine the missing values using the appropriate Ohm's Law equations

Example Calculations

Let's explore three common scenarios using our Resistance Calculator:

Scenario 1: Finding Resistance and Power

Given:

  • Voltage (V) = 12 V
  • Current (I) = 2 A

Enter these values into the calculator and click "Calculate". The results will show:

  • Resistance (R) = 6 Ω
  • Power (P) = 24 W

Scenario 2: Finding Current and Power

Given:

  • Voltage (V) = 12 V
  • Resistance (R) = 6 Ω

Enter these values and calculate. The results will show:

  • Current (I) = 2 A
  • Power (P) = 24 W

Scenario 3: Finding Voltage and Power

Given:

  • Current (I) = 2 A
  • Resistance (R) = 6 Ω

Enter these values and calculate. The results will show:

  • Voltage (V) = 12 V
  • Power (P) = 24 W

These examples demonstrate how you can use the Resistance Calculator to find any unknown electrical value when you have at least two known values. This tool is invaluable for quickly solving Ohm's Law problems in various electrical circuits.

Ohm's Law Circuit Diagram

V R I

This diagram illustrates a simple circuit that follows Ohm's Law. The voltage source (V) provides the electrical potential, the resistor (R) controls the flow of current, and the current (I) flows through the circuit. The relationship between these components is governed by Ohm's Law, allowing us to calculate any one value when the other two are known.

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