Physics
Ohm's law for the whole network
Once the total is known, the supply current follows from the supply voltage.
The Formula
I = V / R
Once the total is known, the supply current follows from the supply voltage.
| Symbol | Meaning | Unit | Notes |
|---|---|---|---|
| I | Current | amperes | The current drawn from the supply, in amperes. |
| V | Supply voltage | volts | The voltage across the network, in volts. |
| R | Total resistance | ohms | The equivalent resistance, in ohms. |
What Each Symbol Means
Iamperes
Current
The current drawn from the supply, in amperes.
Vvolts
Supply voltage
The voltage across the network, in volts.
Rohms
Total resistance
The equivalent resistance, in ohms.
See It Worked With Real Numbers
A formula on its own does not tell you which number goes where. The how to calculate total resistance page applies this equation to a concrete case, shows every intermediate step, and names the mistakes that produce a wrong answer even when the algebra is right.
Where This Formula Appears
This equation is the working core of How To Calculate Total Resistance, filed under Science. Every number the guide produces comes from substituting into this one line.