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Voltage Divider Calculator
Vout = Vin × R2 / (R1 + R2). Solve for any unknown. Includes loading-effect calculation when output drives a load.
MATHVout = Vin × R2 / (R1 + R2). Solve for any unknown. Includes loading-effect calculation when output drives a load.
Detailed instructions, formula notes, and US-context guidance shown in the calculator above.
Disclaimer: Estimate only. Consult a qualified professional for decisions with major financial, legal, or health consequences.
Voltage Divider Calculator
Vout = Vin × R2 / (R1 + R2). With load resistor R_L, R2 effectively becomes R2 ∥ R_L.
Vout (unloaded)
4.0000 V
Vout (with load)3.8710 V
Loading error0.1290 V
For minimal loading error, R_L should be ≥10× R2. Voltage dividers are not good power supplies — current draw collapses the output. Use a voltage regulator IC for real loads.
Frequently Asked Questions
What is the Voltage Divider Calculator for?
Vout = Vin × R2 / (R1 + R2). Solve for any unknown. Includes loading-effect calculation when output drives a load.
How do I use the Voltage Divider Calculator?
Detailed instructions, formula notes, and US-context guidance shown in the calculator above.
How accurate are my voltage divider results?
Estimate only. Consult a qualified professional for decisions with major financial, legal, or health consequences.
Is the Voltage Divider Calculator free to use?
Yes - every calculator on WhichCalc is completely free with no signup, no usage limits, and no tracking on the calculation itself. Results display instantly in your browser and your inputs are never sent to a server. Bookmark the page if you use this calculator regularly.