A clearer view of your numbers
Instrument Accuracy Specification Calculator
Interpret a stated percentage or count specification using an explicit single-term or additive convention.
Browser-local calculations · No login · No financial values sent
Your inputs
01 / EnterThese are editable examples, not recommended rates. Enter your own numbers.
Your result
02 / UnderstandLoading the example calculation…
Show the math
Calculations retain numerical precision. Displayed quantities are rounded to significant digits, not to cents.
What this means
A specification may refer to the magnitude of a reading, an explicitly defined full scale, a span, or display counts. This tool translates only the convention you select into a symmetric absolute limit.
Worked example
At 100 V, 0.5% of reading is 0.5 V. Adding 0.2% of an explicitly defined 200 V full scale (0.4 V) and 2 counts at 0.01 V/count (0.02 V) gives ±0.92 V, only if the manufacturer specifies that additive rule.
How the math works
Reading term = |reading|×reading%/100. Full-scale term = entered full-scale magnitude×FS%/100. Span term = |upper−lower|×span%/100. Count term = integer counts×resolution. The selected term, or explicitly selected additive sum, is the limit L; displayed bounds are indication±L.
About this estimate
No root-sum-square, asymmetric, temperature, frequency, time-since-calibration or range-switch rules are inferred. All unselected components are ignored. Zero percentage/count contributions do not require their scale, endpoints or resolution. The reading remains required to center the displayed bounds. If the instrument specification cannot be represented here, consult its documentation. These are specification bounds, not measurement uncertainty, guaranteed true-value bounds or a calibration pass/fail judgment.
Reference conventions
Keep working through it
Related calculators for the next question.
Calibration Error & Correction Calculator
Compare an instrument indication with a reference and distinguish signed error from additive correction.
Open calculator Calibration & MetrologyMeasurement Repeatability & Statistics Calculator
Summarize repeated measurements with a mean, sample deviation and standard uncertainty of the mean.
Open calculator Calibration & Metrology4–20 mA Signal Scaling Calculator
Convert current and engineering values in either direction across a linear 4–20 mA span.
Open calculatorNeed a different calculation? Suggest a calculator.
Formula v1.0.0 · Reviewed · Tool ID: instrument-accuracy-specification