Analog to Digital ADC Formula and Calculator

This tool calculates the digital output of an Analog-to-Digital Converter (ADC) for a given analog input level.

Table of Contents


To use this tool, input the following:

  • Analog Input Voltage
  • Reference Voltage
  • Number of bits in the ADC


The digital output from an ADC is given by the following formula for an n-bit ADC.

Digital output = 2n * (Analog Input Voltage)/(Analog Reference Voltage)

The input voltage should not exceed the reference level


Consider a 10 bit ADC. The reference voltage is 5 Volt and the input voltage is 1 Volt. The digital output is 205. The binary equivalent of this number output from the ADC is 11001101.


Analog-to-digital Converter (ADC) as the name suggests, is an electronic circuit that is used to convert an analog input signal to a digital value.

A number in this format that can be processed by a microcontroller or digital circuit.

The ADC performs this conversion by using a combination of discrete electronics, such as resistors and capacitors, to convert the continuous analog signal into a series of discrete digital values. This process involves charging a capacitor with the input analog voltage and then holding it at this value for a specified minimum time duration.

The analog value is measured and converted to a digital value using a process called quantization.

The resolution of an ADC is determined by the number of discrete values it can represent. For example, an 8-bit ADC can represent 28 = 256 discrete values, while a 16-bit ADC can represent 65,536 discrete values.

Overall, the ADC plays an important role at the interface between analog and digital systems.

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