Ohm's Law Current
Use Ohm's law to calculate current from voltage and resistance.
How to use
- Enter voltage V.
- Enter a non-zero resistance R and calculate.
Capabilities and scope
The voltage across a resistor is divided by resistance to get ideal resistive current.
How it works
It uses I=V/R.
Example
V=12 V and R=6 Ω give I=2 A.
Useful for
- Estimate current through a resistor load
- Check a simple source-resistance combination
Before you use it
- The formula is undefined at R=0 and does not model real current limiting or source resistance.
Frequently asked questions
Does lower resistance always mean more current?
At the same ideal voltage, this equation gives an inverse relationship.