Voltage divider calculator

Solve any one of Vin, Vout, R1, R2 from the other three — with the nearest E24 resistor suggestion.

Leave exactly one field empty — that is the value solved for.

Unloaded divider: Vout = Vin × R2 ÷ (R1 + R2). Any load on Vout pulls it down — for accurate circuits buffer it or use much smaller resistors. Solving is symbolic: a field left empty is computed exactly.

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How to use

  1. Fill three of the four fields.
  2. Leave the unknown field empty and solve.
  3. Check the E24 nearest-value suggestion.

What it supports

Unloaded divider only — a load on Vout changes the result. Solved symbolically, so the empty field is computed exactly; E24 suggestion re-checks Vout for the nearest real resistor.

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