Ohm's Law Calculator

Calculate voltage, current, resistance, and power using Ohm's Law formulas

Input Parameters

V
A
Ω
W

Results & Formulas

Enter any two values and click Calculate to see results

Circuit Diagram

R V I P = V × I = I² × R = V² / R

Ohm's Law Formulas

Basic Ohm's Law

V = I × R

Voltage = Current × Resistance

Current Calculation

I = V / R

Current = Voltage / Resistance

Resistance Calculation

R = V / I

Resistance = Voltage / Current

Power Calculation

P = V × I

Power = Voltage × Current

When to Use Ohm's Law Calculator

Circuit Design

Calculate component values when designing electronic circuits. Determine the right resistor values for LED circuits, voltage dividers, and current limiting applications.

Electrical Education

Perfect for students and teachers studying electrical engineering fundamentals. Verify homework calculations and understand the relationship between electrical parameters.

Power Consumption Analysis

Calculate power consumption of electrical devices and components. Useful for energy audits, battery life calculations, and power supply design.

Troubleshooting Circuits

Diagnose circuit problems by calculating expected values and comparing with measured values. Identify faulty components and validate circuit behavior.

Component Selection

Choose appropriate components for electronic projects. Calculate required resistor wattage ratings, determine current-limiting resistor values, and size power supplies.

Safety Calculations

Ensure electrical safety by calculating current flows and power dissipation. Verify that components can handle expected electrical loads without overheating or damage.

Frequently Asked Questions

What is Ohm's Law Calculator?

Ohm's Law Calculator is a free online tool that calculates electrical parameters (voltage, current, resistance, and power) using Ohm's Law formulas. Enter any two known values to calculate the remaining parameters instantly. It's designed for engineers, students, and anyone working with electrical circuits.

How do I use the Ohm's Law Calculator?

Simply enter values for any two electrical parameters (voltage, current, resistance, or power) in their respective input fields and click the "Calculate" button. The tool will automatically compute the remaining two values using Ohm's Law equations and display the results along with the formulas used.

What are the Ohm's Law formulas?

The basic Ohm's Law formulas are: V = I × R (Voltage = Current × Resistance), I = V / R (Current = Voltage / Resistance), R = V / I (Resistance = Voltage / Current). Power calculations include: P = V × I, P = I² × R, and P = V² / R.

Is this Ohm's Law Calculator free to use?

Yes, this Ohm's Law Calculator is completely free to use. No registration, downloads, or payments are required. You can calculate electrical parameters unlimited times without any restrictions or hidden costs.

What units does the calculator support?

The calculator supports standard electrical units: Volts (V) for voltage, Amperes (A) for current, Ohms (Ω) for resistance, and Watts (W) for power. All results are displayed in these standard SI units for consistency and accuracy.

Can I use this calculator for AC and DC circuits?

This calculator is designed primarily for DC circuits and resistive AC circuits where voltage and current are in phase. For complex AC circuits with reactive components (inductors and capacitors), specialized AC analysis tools may be more appropriate as they require impedance calculations.

Why do I need to enter only two values?

According to Ohm's Law, if you know any two electrical parameters (voltage, current, resistance, or power), you can calculate the remaining parameters using the established relationships between them. Entering more than two values might create conflicting constraints that violate Ohm's Law.

Is my data secure when using this calculator?

Yes, all calculations are performed locally in your browser. No data is sent to external servers or stored anywhere. Your electrical calculations and input values remain completely private and secure on your device.

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