Voltage Divider

Choose the unknown, then enter the three known values. The result updates while typing; switching unknown preserves each draft. R₁ connects input to output, R₂ output to ground; optional Rₗ is parallel to R₂. Vout=Vin·(R₂∥Rₗ)/(R₁+R₂∥Rₗ), unloaded Rₗ=∞. Source current flows through R₁ and splits between R₂ and the load. Power uses voltage drop times branch current; total power is Vin·I. Load affects inverse solutions too. Zero resistors represent ideal shorts: R₁=0 gives Vout=Vin; R₂=0 or Rₗ=0 grounds output. Two parallel ideal shorts do not determine individual branch currents (—); total current remains calculable if R₁>0. Underdetermined or impossible inverse cases return an error, never an invented resistance. At Vin=0 the displayed voltage ratio is undefined (—). Nonnegative ideal DC values only; no tolerances, AC impedance, settling or component rating advice. Input ranges: voltage0…10⁶V, resistance0…10¹²Ω; arithmetic limits, not device limits. Tiny nonzero results use scientific notation. Drafts survive navigation/reload. A voltage divider is not a regulated supply.