Electrical · Free Calculator
Voltage Divider Calculator
Calculate the output of a two resistor voltage divider. Add a load resistance to see how much it pulls the output down.
Vout = Vin × R2/(R1+R2)Loaded dividerDivider currentResistor power
V
Output voltage7.6735 V
Unloaded output7.6735 V
Divider current1.633 mA
Power in R126.66 mW
Power in R212.53 mW
How this result was calculated
- No load connected
- Vout = Vin × R2 ÷ (R1 + R2) = 7.6735 V
Advertisement
Voltage Divider Formula
Vout = Vin × R2 ÷ (R1 + R2)
With load: replace R2 by R2 ∥ RL
With load: replace R2 by R2 ∥ RL
Worked example
24 V across 10 kΩ and 4.7 kΩ gives 24 × 4.7 ÷ 14.7 = 7.67 V, drawing 1.63 mA.
Key insight: keep the load at least ten times larger than R2, otherwise the output drops noticeably. Dividers are fine for reference signals but not for powering circuits.
Advertisement
Frequently Asked Questions
How does a voltage divider work?
The same current flows through both resistors, so the voltage splits in proportion to their resistances.
How do I choose divider resistor values?
Pick the ratio for the output you need, then scale both values so the divider current is well above the load current but power loss stays acceptable.
Can I use a voltage divider to read 24 V on a 5 V input?
Yes, for example 39 kΩ over 10 kΩ gives about 4.9 V from 24 V. Add protection for transients in industrial wiring.
You May Also Like
Learn more on the blog
Basics of Ohm's law
A practical, field focused guide on instrumentationblog.in that explains the theory behind this calculator and how engineers apply it on real plants.
Read Full ArticleMore Electrical Calculators
Power Factor Correction CalculatorkVAR, µF per phasekW to Amps CalculatorkW to A, 1 phase and 3 phaseAmps to kW CalculatorA to kW, 1 phase and 3 phasekVA to Amps CalculatorkVA to A, GeneratorskW to kVA CalculatorkW ↔ kVA, kVARPower Triangle CalculatorkW, kVAR, kVA, Power factorElectricity Cost CalculatorkWh, Daily, monthly, yearlyVoltage Unbalance CalculatorNEMA MG1 method, Three phaseCable Size and Voltage Drop CalculatorDC, 1 phase, 3 phase, Copper and aluminiumCable Resistance CalculatorCopper and aluminium, Temperature correctedCable Short Circuit Rating CalculatorAdiabatic equation, Earth conductor sizeTransformer Current and Short Circuit CalculatorFull load current, Short circuit currentIDMT Relay Operating Time CalculatorIEC 60255 curves, TMSEarth Fault Loop Impedance CalculatorZs = Ze + R1 + R2, MCB type B, C, DMotor Full Load Current CalculatorkW and HP, Three and single phaseMotor Torque CalculatorkW to N·m, HP to lbf·ftSynchronous Speed and Slip CalculatorNs = 120f/P, Slip %Star Delta Starter CalculatorDOL vs star delta, Starting currentVFD Frequency and Speed CalculatorHz to rpm, rpm to HzTransformer Turns Ratio CalculatorTurns ratio, Voltage ratioOhm's Law CalculatorV = I × R, P = V × ISeries and Parallel Resistor CalculatorSeries, ParallelCapacitive and Inductive Reactance CalculatorXc = 1/(2πfC), XL = 2πfLLC Resonant Frequency Calculatorf = 1/(2π√LC), Find L or CRC Time Constant Calculatorτ = R × C, ChargingLED Resistor CalculatorR = (Vs − Vf) ÷ I, E24 standard valueResistor Color Code Calculator4 band, 5 bandCapacitor Series and Parallel CalculatorSeries, ParallelCapacitor Energy and Charge CalculatorE = ½CV², Q = CVAWG to mm² Wire Size CalculatorAWG to mm², mm² to AWGDecibel (dB) CalculatorPower ratio, Voltage ratioDelta Star (Δ Y) Conversion CalculatorΔ to Y, Y to ΔBattery Backup Time CalculatorRuntime, Required AhUPS Sizing CalculatorkVA and kW, Growth marginLighting Lumen CalculatorLumen method, Lux levelEarth Rod Resistance CalculatorDwight formula, Soil resistivity
More Calculator Categories
Temperature Measurement15 live toolsInstrumentation Signal4 live toolsPLC Digital Signal3 live toolsFlow Measurement19 live toolsLevel Measurement12 live toolsPressure Measurement13 live toolsControl Valve12 live toolsCalibration10 live toolsSafety and SIL7 live toolsAnalytical8 live toolsUnit Converters76 converters, 700+ units