How to Use the Voltage Divider Calculator
The Voltage Divider Calculator is so simple-to-use that you just need to enter the values of R1 and R2 resistors, the value of the input voltage. Then the online calculator will calculate and display the output voltage result automatically.
Step 1: Enter the value of the Voltage input at the first box.
Step 2: Input the value of the 1st resistance R1 in the second blank box.
Step 3: Enter the value of the 2nd resistance R2 at the third box.
Step 4: Input the number of Load(RL).
Step 5: The result will automatically display.
What is a voltage divider?
A potential divider circuit is a typical circuit in electronics that converts an input voltage to a voltage that is less than it. This circuit is very useful for all analog circuits that include variable voltages, so it's crucial to understand how it operates and how to measure the resistor values.
How to Find the Output Voltage of a Divider Circuit
As seen above, a voltage divider circuit is a very simple circuit with only two resistors (R1 and R2). Using the resistor R2, the appropriate output voltage (Vout) can be obtained. We can convert an input voltage to the specified output voltage by using these two resistors; the output voltage is determined by the resistance R1 and R2.
Voltage Divider Output Formula
The formular to calculate Vout is:
Vout= (Vin x R2) / (R1 + R2)
Where, Vout= Output Voltage Vin=Input Voltage and R1=Upper Resistor R2=Lower resistor
We would need an Ohms law calculator to understand how potential diver formulae are derived. According to Ohms law, the voltage drop in any position is a function of the current flowing through the circuit and the resistance across it.
Current flowing via resistance over a voltage = voltage voltage voltage voltage voltage voltage voltage voltage voltage voltage voltage voltage voltage voltage voltage voltage voltage voltage voltage voltage voltage voltage voltage voltage voltage voltage
Let's use this to figure out the Input Voltage (Vin) for the circuit above. Since two resistors are connected across the input voltage Vin, Input Voltage = Current (Resistance 1 + Resistance 2) Vin = I (R1 + R2) (1)
Calculate the output voltage (Vout) similarly; there is just one resistor (R2) through it, so
Current x Resistance = Output Voltage R2
Vout = I × R2 (2)
We can see that the value of current in equations 1 and 2 is the same, so let's rewrite them.
I = Vin / (R1 + R2) is the first equation.
I = Vout /R2 is the second equation.
Since the current flowing through the circuit is constant, the current I for both equations would be the same, so we can compare them as
Vout /R2 = Vin / (R1 + R2)
Vout= (Vin x R2) / (R1 + R2)
Example Calculation
Let us test this voltage divider formulae for the above circuit where Vin =5V, R1 = 1000ohms and R2 = 2000ohms.
Vout = (5×2000) / (1000/2000)
Vout = (10000) / (3000)
Vout = 3.3333V
Another critical consideration when choosing resistor values is the power rating (P). Once you have the values for I (based on load), Vin, R1 and R2, multiply R1 and R2 to get RTOTAL, and use the Ohms law calculator to determine the power (Watts) rating for the resistors. Alternatively, you can use the formula P=VI to determine the power rating of your resistor. The resistor will overheat and possibly burn if the correct Power rating is not chosen.
