SINAD ↔ ENOB Calculator
Convert between SINAD (dB), ENOB (effective bits), and THD+N for ADC/DAC characterization. The classic test-report conversion formulas.
How to Use
- Enter either SINAD (dB) or ENOB (bits); the other updates.
- Also shows equivalent THD+N and ideal quantization SNR for the bit depth.
Show Work
Formulas
History of SINAD / ENOB
The SINAD and ENOB metrics were formalized in the 1980s as sigma-delta and pipelined ADC architectures surpassed the simple flash ADCs of earlier eras. Walt Kester's ADI data-conversion handbooks (1992, 2005) codified the standard measurement procedure: apply a pure sine wave at the ADC input, FFT the output, compute signal-to-noise-plus-distortion ratio, convert via ENOB = (SINAD - 1.76)/6.02 to an effective bit depth. Today every production ADC datasheet reports SINAD and ENOB as primary specs alongside resolution.
About This Calculator
Enter either SINAD (from FFT of pure-tone ADC capture) or ENOB; the other updates via ENOB = (SINAD − 1.76) / 6.02. Also reports equivalent THD+N percentage and the theoretical ideal SINAD for the specified ADC bit depth.
Walt Kester\'s ADI "Data Conversion Handbook" (2005) is the canonical reference for ADC characterization. Everything runs client-side.
About the SINAD ↔ ENOB Calculator
Whether you are at a desk or on your phone, the SINAD ↔ ENOB Calculator makes electronics and circuit design easy — and it is completely free. Convert between SINAD (dB), ENOB (effective bits), and THD+N for ADC/DAC characterization. The classic test-report conversion formulas.
How it works
Type your numbers into the boxes. The answer shows up right away — you do not have to press a button. If you change a number, the answer changes too. So you can try different numbers and watch what happens, or check an answer you worked out yourself. Just make sure each box has the right kind of number in it.
Want the deeper story? The Knowledge Base explains the ideas behind the tools in more detail.
Frequently Asked Questions
What is SINAD?
Signal-to-Noise-And-Distortion ratio: ratio of signal power to total noise + harmonic distortion power, in dB. Measured from FFT of an ADC capturing a pure sine wave.
ENOB?
Effective Number Of Bits: SINAD converted back to bit-depth equivalent, via 6.02·ENOB + 1.76 = SINAD. A 16-bit ADC with SINAD = 90 dB has ENOB = 14.7 bits — 1.3 bits are lost to real-world noise.
THD+N vs SINAD?
Same thing, different sign. THD+N in dBc (down from signal) = -SINAD. For a 90 dB SINAD signal, THD+N = -90 dBc = 0.003%.
How do I use the SINAD ↔ ENOB Calculator?
Simply type your numbers and read the result, which refreshes the instant you change something. There is nothing to submit and nothing to wait for.
Is it free? Does it work without internet?
Yes to both. It is free with no sign-up, and once the page has loaded it keeps working even with no internet.
Where does my data go?
Nowhere — every calculation runs on your own device. Nothing you enter is uploaded, logged, or stored.
Common Use Cases
Audio ADC
AK5574 audio ADC: 114 dB SINAD, 18.6 ENOB from 24-bit output.
Oscilloscope
1 GS/s, 8-bit: 44 dB SINAD, 7.0 ENOB at low frequencies.
RF ADC
ADC for SDR: 75 dB SFDR → ~72 dB SINAD → ~11.7 ENOB at Nyquist.
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