ADC Calculator

An Analog-to-Digital Converter (ADC) translates a real-world voltage signal into a discrete digital number — this calculator shows you exactly what that number will be for any combination of bit depth and voltage. Enter your Number of Bits, Analog Input Voltage (Vin), and Reference Voltage (Vref) to get the Digital Output Value and its binary representation. Secondary outputs include ADC resolution, step size (LSB), maximum digital value, and the input as a percentage of full scale. Also try the find Logic Gate with Logic Gate Truth Table Calculator.

Results

Digital Output Value

Binary Output

ADC Resolution

Step Size (LSB)

Maximum Digital Value

Input Percentage of Full Scale

What is ADC resolution and how does it affect accuracy?

ADC resolution is the number of bits used to represent the digital output. Higher resolution provides more precise conversion - a 10-bit ADC has 1024 levels while a 12-bit ADC has 4096 levels, offering finer granularity. See also our Hex to ASCII Converter.

How do I calculate the step size (LSB) of an ADC?

Step size (Least Significant Bit) is calculated as Reference Voltage ÷ (2^n), where n is the number of bits. For example, a 10-bit ADC with 5V reference has a step size of 5V ÷ 1024 = 4.88mV.

What happens if input voltage exceeds the reference voltage?

If the input voltage exceeds the reference voltage, the ADC will output its maximum digital value (2^n - 1). This is called saturation or clipping, and the actual input voltage cannot be determined. You might also find our calculate Nyquist Frequency, Aliased Harmonics in Band & Spurious Free Dynamic Range — ADC Spurious useful.

Why do microcontrollers need ADC converters?

Microcontrollers can only process digital signals (0s and 1s). ADCs convert continuous analog signals from sensors and real-world inputs into discrete digital values that microcontrollers can understand and process.

What's the difference between 8-bit, 10-bit, and 12-bit ADCs?

The main difference is resolution: 8-bit ADCs have 256 levels, 10-bit have 1024 levels, and 12-bit have 4096 levels. Higher bit ADCs provide more precise measurements but may be slower and consume more power.

How accurate is this ADC calculator?

This calculator uses the standard ADC conversion formula: Digital Value = floor((Vin/Vref) × (2^n - 1)). It provides theoretical values - actual ADC performance may vary due to noise, non-linearity, and other real-world factors.