Voltage Divider Calculator
Calculate output voltage, divider current, resistor power, equivalent resistance, and loaded voltage for a two-resistor voltage divider.
Calculator Mode
Input Values
Voltage Divider Result
Output Voltage
4.86 V
Divider Ratio: 40.48%
Output Voltage
4.86 V
Divider Current
0.714 mA
Equivalent Resistance
4.048 kΩ
Divider Power
8.64 mW
R1 Power
5.10 mW
R2 Power
3.54 mW
Load Current
—
Voltage Divider Circuit
R1
Vout
R2
RL
⏚
Vin
Calculation Steps
Enter values and click Calculate.
Voltage Divider Formulas
Basic Voltage Divider:
Vout=Vin× R2/ (R1+ R2)
Vout=Vin× R2/ (R1+ R2)
Divider Current:
I=Vin/ (R1+ R2)
I=Vin/ (R1+ R2)
Equivalent Resistance:
Req=R1+ R2
Req=R1+ R2
R1 Power:
PR1=I² × R1
PR1=I² × R1
R2 Power:
PR2=I² × R2
PR2=I² × R2
Loaded Voltage Divider:
R2,eff=R2∥ RL
R2,eff=(R2× RL) / (R2+ RL)
Vout=Vin× R2,eff/ (R1+ R2,eff)
R2,eff=R2∥ RL
R2,eff=(R2× RL) / (R2+ RL)
Vout=Vin× R2,eff/ (R1+ R2,eff)
Voltage Divider Design
A voltage divider can be designed when the input voltage, desired output voltage, and one resistor value are known.
Calculate R2:
R2=R1× Vout/ (Vin− Vout)
R2=R1× Vout/ (Vin− Vout)
Calculate R1:
R1=R2× (Vin− Vout) / Vout
R1=R2× (Vin− Vout) / Vout
Example Calculation
Consider a voltage divider with a 12 Vinput, 10 kΩR1, and 6.8 kΩR2.
Vout=12 × 6800 / (10000 + 6800)
Vout≈ 4.86 V
Vout≈ 4.86 V
The divider current is approximately 0.714 mA.