ADC Resolution Calculator
Calculate ADC step size, dynamic range and quantisation error for a given resolution.
About ADC Resolution Calculator
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.
Formula
ADC Resolution
Step size = V_ref ÷ 2^n; dynamic range ≈ 6.02n + 1.76 dB
- LSB
- Least significant bit, the smallest voltage change the converter resolves
- 6.02 dB
- Dynamic range gained per additional bit
Worked example
With the default values below, ADC Resolution Calculator returns Step Size of 0.805664. Change any input above and every figure here is recalculated in your browser.
Inputs used
- ADC resolutionaccepts 1–32 bits
- 12 bits
- Reference voltageminimum 0.001 V
- 3.3 V
- Signal amplitudeminimum 0 V
- 1 V
Results
- Step Size
- 0.805664 mV
- Quantisation Levels
- 4,096
- Theoretical Dynamic Range
- 74.000 dB
- Maximum Quantisation Error
- 0.402832 mV
- Bits Actually Exercised by the Signal
- 10.278 bits
Step by step
- 1Values used
- 2ADC Resolution
- 3Step Size= 0.805664 mV
- 4Quantisation Levels= 4,096
- 5Theoretical Dynamic Range= 74.000 dB
- 6Maximum Quantisation Error= 0.402832 mV
- 7Bits Actually Exercised by the Signal= 10.278 bits
Assumptions and limits
- The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 6 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
How is ADC Resolution calculated?
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.
Why does ADC Resolution matter?
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.
What values do I need to enter?
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.