Calculate ADC step size, dynamic range and quantisation error for a given resolution.
Each additional bit halves the step size and adds about 6 dB of dynamic range. A signal that uses only part of the reference range exercises fewer bits, wasting resolution — which is why input scaling matters as much as converter choice. A 12-bit converter measuring a signal at a tenth of full scale delivers only about 8.7 effective bits, so amplifying before conversion is usually better than buying a bigger ADC.
ADC Resolution
Step size = V_ref ÷ 2^n; dynamic range ≈ 6.02n + 1.76 dB
Step size = V_ref ÷ 2^n; dynamic range ≈ 6.02n + 1.76 dB Each additional bit halves the step size and adds about 6 dB of dynamic range. A signal that uses only part of the reference range exercises fewer bits, wasting resolution — which is why input scaling matters as much as converter choice.
A 12-bit converter measuring a signal at a tenth of full scale delivers only about 8.7 effective bits, so amplifying before conversion is usually better than buying a bigger ADC.
This calculator takes 3 inputs: ADC resolution, Reference voltage, Signal amplitude. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.