ADC Resolution Calculator
Calculate ADC voltage resolution (LSB size), the number of steps, and the voltage at any digital reading. Covers Arduino Uno (10-bit), ESP32 (12-bit), STM32 (12-bit), and Raspberry Pi ADC hats.
ADC Resolution & Voltage Conversion
An ADC (Analog-to-Digital Converter) converts continuous voltages into discrete digital steps. Resolution (in bits) determines step size. A 12-bit ADC divides 0–3.3V into 4096 steps, each about 0.8 mV. Use this to convert raw ADC readings to voltage or understand precision limits on Arduino, ESP32, or STM32.
Analog signal (dashed) quantized into discrete steps. Each step = 1 LSB = Vref / 2^bits
Arduino Uno: 10-bit, ESP32: 12-bit, STM32: 12-bit
Usually 3.3V or 5V
Digital value from analogRead()
Voltage
1.650 V
- Total steps
- 4,096
- LSB size
- 0.81 mV
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