12 bit ADC Conversion Formula and Calculator

This tool provides the Analog-to-Digital Converter resolution and the digital value for an analog signal input to a 12-bit ADC.


  • Input Voltage Vin
  • Reference Voltage Vref
  • Number of bits

Formula for 12-bit ADC

The analog resolution or the smallest value that can be measured by the ADC is given by the formula:



  • Vref is the reference voltage

The digital output from an ADC is given by the following formula for a 12-bit ADC.

Digital output = 212 * (Vin)/(Vref)


  • Vin is the analog input
  • Vref is the analog reference

Example Calculation for 12-bit ADC

For example, if an 12-bit ADC has a reference voltage (Vref) of 5V, the smallest change it can detect (quantum) is Vref / 212 = 5V / 4096 ≈ 1.22 mV. This means each step of the digital output corresponds to a change of about 1.22 mV in the input signal.

Analog input voltage of 1 Volt gives a digital output level of 1100110011.


What is a 12-bit ADC?

An 12-bit Analog-to-Digital Converter (ADC) is a device that converts analog signals into digital signals. The “12-bit” part refers to the resolution of the ADC, meaning it can produce 212 = 4096 discrete values.

A 12-bit ADC is commonly used in applications where moderate resolution is sufficient and where a balance between cost, power consumption, and precision is needed. Examples include:

  • Audio signal processing
  • Industrial automation
  • Medical instrumentation
  • Consumer electronics

Advantages and Limitations


  • Provides a good balance between resolution and conversion speed.
  • Suitable for a wide range of applications.


  • Higher resolutions (e.g., 16-bit or 24-bit) may be needed for applications requiring very high precision.
  • Limited by noise and other analog signal integrity issues, which can affect accuracy.

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