Ohm's Law Calculator
Fill in the values and the answer updates as you type.
How the Ohm's Law Calculator works
Ohm's law: I = V ÷ R. Power: P = V² ÷ R.
Inputs and results
The Ohm's Law Calculator takes 2 inputs and gives 2 results.
What you enter
- Voltage (V) — starts at 12.
- Resistance (Ω) — starts at 6.
What you get
- Current (A)
- Power (W)
Example: Ohm's Law Calculator with the starting values
With voltage 12 V and resistance 6 Ω, the calculator returns:
| Current (A) | 2 |
|---|---|
| Power (W) | 24 |
Change any value above and the results update straight away.
Ohm's Law Calculator FAQ
How do I use the Ohm's Law Calculator?
Enter voltage and resistance in the fields, then read current (a) and power (w) in the result panel. The answer updates as you type, and you can press Calculate or Enter to refresh it. Use “Copy link” to share your exact numbers with someone else.
What does the Ohm's Law Calculator calculate?
Current and power from voltage and resistance. It returns current (a) and power (w) from the 2 values you provide.
What values does the Ohm's Law Calculator start with?
It opens with voltage 12 V and resistance 6 Ω so you can see a working result straight away. Replace them with your own numbers, or press Reset to return to these starting values.
Is the Ohm's Law Calculator free and private?
Yes. It is free, needs no account, and runs in your browser, so nothing you type is sent to or stored on our servers. See the Privacy Policy for details.
Can I rely on the Ohm's Law Calculator for important decisions?
Treat the result as a well-rounded estimate. Real situations often have details a general calculator cannot know, so confirm important decisions with a qualified professional. See the Disclaimer for more.