Loaded Voltage Divider Calculator
Compare unloaded and resistively loaded divider voltage, branch currents and dissipation.
YOUR CALCULATION
Result
—
Calculation steps
Work through one step at a time or reveal the complete calculation. The steps use your current inputs.
How to calculate
Replace the lower resistor and output load by their parallel equivalent, apply the voltage-divider relation, then calculate each branch current and power.
Rbottom-effective=(1/Rbottom+1/Rload)^−1; output=source×Rbottom-effective/(Rtop+Rbottom-effective)
Worked example
A 12 V source and two 10 kΩ divider resistors give 6 V unloaded. Adding a 10 kΩ load gives a 5 kΩ lower equivalent and 4 V output. Source current is 0.8 mA; lower and load currents are 0.4 mA each.
Assumptions and input details
Ideal DC voltage source and positive constant resistors. No tolerance, temperature coefficient, input capacitance, source current limit or component power rating is assumed. Signed voltage and currents are permitted; dissipated power remains nonnegative. This is a loading analysis, not a component selection or safe-operating certification.
References: Texas Instruments: voltage divider calculations
Unit definitions
Unit selection is independent of language. Each selector contains only units for its physical quantity. Calculations use defined base units internally.
SI prefixes are explicit: for example, milli means one thousandth, micro one millionth and kilo one thousand. Changing a unit changes the interpretation of the entered number.
Using this calculator
Can I enter my own problem?
Yes. Replace the example values with your own inputs. The result, calculation steps, tables and applicable diagrams update from those inputs. Blank or invalid values clear the result; example values are never silently substituted for missing inputs.
Are the results exact?
Results use floating-point arithmetic and displayed rounding. Read the formula, assumptions and any stated data precision before interpreting the result.
Is my input uploaded?
The calculation runs in your browser. No account, file upload or external AI service is required. Inputs are not saved between page reloads.
Enter two electrical quantities to find voltage, current, resistance and power for an ideal DC resistor. Follow the equations and current–voltage graph.
Find the equivalent resistance of 2–20 ideal resistors in series or parallel. Enter a DC voltage to calculate current, voltage drop and power for every resistor.
Compare inverting/non-inverting resistor gain around a reference and apply your entered output-voltage bounds.
Reserved advertising space.