Voltage Divider Calculator
Voltage divider calculator
Compute Vout and check current and resistor power in one panel.
InputsDividerohm • 6 digitsLive
Output voltage
6 V
Divider ratio: 50% of Vin. Estimated no-load current: 6 mA.
Live
0.5
ratio
6
Current (mA)
0.036
Power R2 (W)
2,000
Total R (Ohm)
Output voltage (V)
6
Divider ratio
0.5
Source current (mA)
6
Power on R2 (W)
0.036
Power on R1 (W)
0.036
Total resistance (Ohm)
2,000
Advanced breakdownFormula, steps, and history
LaTeX formula
V_{out}=V_{in}\times\frac{R_2}{R_1+R_2}Step-by-step
- Step 1: Convert resistors to ohms -> R1 = 1,000 Ohm, R2 = 1,000 Ohm.
- Step 2: Compute ratio -> R2/(R1+R2) = 0.5.
- Step 3: Multiply by Vin -> 12 * ratio = 6 V.
Formula
Vout = Vin x (R2 / (R1 + R2)) Symbol legend
| Symbol | Meaning | Unit | Copy |
|---|---|---|---|
V_{\text{in}} | Input/source voltage | V | |
V_{\text{out}} | Output voltage at divider midpoint | V | |
R_1 | Upper resistor connected to source | Omega | |
R_2 | Lower resistor connected to ground | Omega |
- Vin is the input voltage.
- R1 is the top resistor connected to Vin.
- R2 is the bottom resistor connected to ground where Vout is measured.
Example
Worked example: Vin 12 V, R1 1k, R2 1k
- 1 Vin = 12 V
- 2 R2 / (R1 + R2) = 1000 / 2000 = 0.5
- 3 Vout = 12 x 0.5 = 6
Output voltage is 6 V.
How
- Enter input voltage (Vin).
- Enter resistor values for R1 and R2 in ohms.
- Read the output voltage result and divider ratio instantly.
Avoid
- Swapping the resistor position when mapping to R1 and R2.
- Using zero or negative resistor values.
- Assuming the divider is unchanged under heavy load without load analysis.
FAQ
Do R1 and R2 need to use the same unit?
Yes. Any resistance unit works as long as both resistors use the same unit.
Can Vin be zero?
Yes, zero input voltage gives zero output voltage.
Does this include loading effects?
No, this formula assumes an unloaded or very high-impedance output.
Switch
Switch12
No match.