Voltage Divider Formula Calculator
Voltage and Current Divider Calculator works out Output voltage and Current through R1 from Divider type, Input voltage and Total current. The default figures on this page give output voltage of 6 V; change any entry and the result, the working and the sources update together.
Your figures
Updates as you typeHow this is worked out
3 steps
- Series resistance = 1000 + 1000 = 2000 ohm
- Series current = 12 / 2000 = 0.006 A
- Vout = Vin x R2 / (R1 + R2) = 12 x 1000 / 2000 = 6 V
Its 5 worked examples are re-run on every release, last on 15 September 2026. What changed
Sources and references
2 sources
What the Voltage and Current Divider Calculator calculates
Computes the output of a resistive voltage divider, or how a total current splits between two parallel resistors.
How to use this Voltage and Current Divider Calculator
Enter Divider type, Input voltage, Total current and R1. Output voltage updates as you type, and “Use a worked example” loads checked figures you can adjust. Change one figure at a time to see what drives the result.
How the result is worked out
Open “How this is worked out” beside the result for the step-by-step calculation behind Output voltage, Current through R1 and Current through R2.
The method follows Voltage divider: Vout = Vin x R2 / (R1 + R2) and Current divider: I1 = It x R2 / (R1 + R2), I2 = It x R1 / (R1 + R2).
Research R3912-GT-4: 12 A split between 2 and 4 ohm branches example
With Divider type: current, Total current: 12, R1: 2, R2: 4, the calculator returns Current through R1: 8, Current through R2: 4. This example is checked against an independent source in the test suite.
What you can compare
Change one input at a time to see how it affects Output voltage, Current through R1 and Current through R2. The inputs you can vary are Divider type, Input voltage, Total current, R1 and R2.
Results are general information, not financial, tax, legal, medical or engineering advice. Check any decision that matters with a qualified professional.
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Frequently asked questions
How to calculate voltage divider?
Computes the output of a resistive voltage divider, or how a total current splits between two parallel resistors. Open “How this is worked out” beside the result to see each step for your own figures.
How to make a 5V to 3.3 V voltage divider?
It needs Divider type, Input voltage, Total current, R1 and R2. Nothing else is required, and the figures stay in your browser.
What is the voltage divider rule?
On the figures this page opens with — total current 12 A, R1 2 ohm and R2 4 ohm — the output voltage is 6 V. No single number fits everyone: change any figure above and the answer updates as you type, with each step of the arithmetic beside it.
What is the formula for divider?
The result gives Output voltage, Current through R1, Current through R2, Series current, Total resistance and Divider ratio, each labelled with its unit so the figure can be read on its own.
What information do I need for the Voltage and Current Divider Calculator?
You need Divider type, Input voltage, Total current, R1 and R2. The page opens with default figures that give output voltage of 6 V, so you can see the scale before entering your own.
What does this Voltage and Current Divider Calculator show?
It shows Output voltage, Current through R1, Current through R2, Series current, Total resistance, Divider ratio and Total power dissipated, with the working and any warnings for your entries.