Voltage Divider Calculator
Uses Vout = Vin × R2 / (R1 + R2), referenced to the bottom of R2. Supply Vin, R1 and R2 yourself. Assumes ideal positive resistors and no output load; ignores tolerance, heating, source impedance and frequency effects. This does not check circuit ratings, power, safety or design suitability. Results use six significant digits; numerical bounds do not imply physically suitable values. Inputs stay in your browser.
A QUICK WALKTHROUGH
How to use this tool
- Enter Vin in volts and R1/R2 in ohms.
- Calculate the ideal unloaded divider.
- Read Vout and the divider ratio with the model limits.
Vout = Vin × R2 / (R1 + R2)
Uses Vout = Vin × R2 / (R1 + R2), referenced to the bottom of R2. Supply Vin, R1 and R2 yourself. Assumes ideal positive resistors and no output load; ignores tolerance, heating, source impedance and frequency effects. This does not check circuit ratings, power, safety or design suitability. Results use six significant digits; numerical bounds do not imply physically suitable values. Inputs stay in your browser.
GOOD TO KNOW
Common questions
Which formula does this calculator use?
It calculates the ideal unloaded output with Vout = Vin × R2 / (R1 + R2), referenced to the bottom of R2.
Does the result include a connected load?
No. The model assumes no output load and does not account for tolerance, heating, source impedance, frequency, ratings, power, safety, or design suitability.
Are my circuit values uploaded?
No. The calculation runs in your browser and the entered values stay there.