Voltage divider calculator for 3 resistors lets you calculate the voltage divided by three series resistors.

#### Instructions:

- Enter the input voltage.
- Enter resistance of first resistors.
- Enter resistance of the second resistor.
- Enter resistor of the third resistor.
**(The default input for all resistors are in ohms)** - The default voltages are provided with an accuracy of two decimals.

**Formula:**

V_{1} = { R_{1} / (R_{1} + R_{2} + R_{3}) } * V_{in}

V_{2} = { R_{2} / (R_{1} + R_{2} + R_{3}) } * V_{in}

V_{3} = { R_{3} / (R_{1} + R_{2} + R_{3}) } * V_{in}

Let’s solve an example to understand it:

Example # 1: For the circuit diagram shown above, determine the potential dropped across three resistors if R_{1 }= 50 Ω, R_{2 }= 100 Ω and R_{3 }= 50 Ω. The input source is a 12 V dc battery

Solution:

V_{1} = { R_{1} / (R_{1} + R_{2} + R_{3}) } * V_{in }= { 50 Ω / ( 50 Ω + 100 Ω + 50 Ω) } * 12 V = 3 V_{ }

V_{2} = { R_{2} / (R_{1} + R_{2} + R_{3}) } * V_{in }= { 100 Ω / ( 50 Ω + 100 Ω + 50 Ω) } * 12 V = 6 V

V_{3} = { R_{3} / (R_{1} + R_{2} + R_{3}) } * V_{in }= { 50 Ω / ( 50 Ω + 100 Ω + 50 Ω) } * 12 V = 3 V

Let’s solve another example with different values of resistors.

Example # 2: For the same previous circuit, determine the voltage that is dropped across three resistors if their values are R_{1 }= 10 Ω, R_{2 }= 1 kΩ and R_{3 }= 5 kΩ. The input source is a 10 V dc battery. Compare the example with previous one and generalize your observations for any * voltage divider circuit*.

Solution:

V_{1} = { R_{1} / (R_{1} + R_{2} + R_{3}) } * V_{in }= { 10 Ω / ( 10 Ω + 1 kΩ + 5 kΩ) } * 10 V = 0.016 V_{ }

V_{2} = { R_{2} / (R_{1} + R_{2} + R_{3}) } * V_{in }= { 1 kΩ / ( 10 Ω + 1 kΩ + 5 kΩ) } * 10 V = 1.663 V

V_{3} = { R_{3} / (R_{1} + R_{2} + R_{3}) } * V_{in }= { 5 kΩ / ( 10 Ω + 1 kΩ + 5 kΩ) } * 10 V = 8.319 V

Also try our simple VDR calculator and loaded VDR calculator.

There are some observations from both cases:

- The sum of individual voltages V
_{1}, V_{2}, and V_{3 }is equal to overall input.- Case 1: V
_{in }= V_{1}+ V_{2 }+ V_{3}= 3 V + 6 V + 3 V = 12 V - Case 2: V
_{in }= V_{1}+ V_{2 }+ V_{3}= 0.016 V + 1.663 V + 8.319 V = 10 V

- Case 1: V
- The larger the magnitude of resistor, the greater potential drop has it.
- Case 1: R
_{2}> R_{1}> & R_{2}> R_{3 }, V_{2}> V_{1}> & V_{2}> V_{3 } - Case 2: R
_{3}> R_{2}> R_{1 }, V_{3}> V_{2 }> V_{1}

- Case 1: R
- A very small resistor has negligible voltage dropped across it as compared to a very large resistor.
- Case 2: Likewise R
_{3}is 500 times greater than R_{31}, the V_{3}is also very large as compared to V_{1}.

- Case 2: Likewise R