Convertisseur d'unites
Guide : Percent Error and Significant Figures in Converted Values
Ce guide explique How rounding, measured precision, and percent error affect values moved between calculators and reports.
Methode
Use this guide when a converted number affects lab notes, schoolwork, specifications, spreadsheet checks, and quality reports. A reliable result keeps the original value, source unit, target unit, conversion factor, and rounding choice visible.
The goal is not to memorize every factor. The goal is to make the calculation traceable enough that someone else can review it later.
Liste de controle
- Keep the original measured precision visible.
- Round converted values only after the final calculation.
- Use percent error when comparing a measured value with an accepted value.
Fait utile
Exact conversion factors do not add measurement precision to the original value.
Exemples pratiques
Percent error = absolute error / accepted value x 100.
2.54 cm per inch is exact, but a ruler reading may not be exact.
A value measured to 0.1 should not be reported with unnecessary decimal places.
Questions frequentes
What should I check first?
Confirm the source unit and target unit before changing the number.
When should I round?
Round at the end, after formulas and related conversions are complete.
Which calculator should I use next?
Use the related calculators below to check the main values from this guide.
Calculateurs associes
Point cle
A useful conversion is traceable: it shows the original unit, the target unit, the factor used, and the rounding decision.