Ohm’s Law Calculator (Voltage, Current, Resistance, Power)
Science ToolsFind voltage, current, resistance and power
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All history →Ohm’s Law Calculator (Voltage, Current, Resistance, Power) — at a glance
Fill in any two values and get the rest.
V = 12
R = 4
Calculate
I = 3 A
P = 36 W
How to use it — step by step
Just your input — nothing to install or sign up for.
1
Enter your values
Fill in the boxes. Sample values are already there so you can see how it works.
2
Calculate
Press the button to get your answer instantly.
3
Read the result
The main answer is shown in a large card with extra details below it.
4
Copy it
Use the copy button to save the result anywhere.
Pro tips
Small things that make the result better.
✦Fill exactly two boxes and leave the other two empty.
✦Voltage is in volts (V), current in amperes (A), resistance in ohms and power in watts (W).
Quick facts
Freeno signup, no limit
Instantresult in a moment
Privatenothing is uploaded
Any devicephone, tablet or PC
Frequently Asked Questions
Is my data safe?+
Yes. Everything runs inside your own browser. Your text, files and images are never uploaded to any server.
Is this tool really free?+
Yes — completely free, no signup, no watermark and no usage limit.
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