Accuracy guide
Measurement Accuracy Guide
Accurate conversion is not only about the formula. It also depends on rounding, source precision, measurement tools, and how the answer will be used.
Use enough decimal places
For everyday planning, a rounded result is usually fine. For engineering, medicine, finance, aviation, or safety work, keep more digits and verify the standard used.
Respect significant figures
A conversion result should not imply more precision than the original measurement. If the input is approximate, the converted result is also approximate.
Check unit variants
Some unit names have variants. A US gallon and an imperial gallon are different. A calorie and a kilocalorie may be confused in nutrition contexts.
Know when formulas are special
Temperature and fuel economy are common cases where conversion is not a simple multiplication in both directions. Always use the correct formula.
Verify critical work
For legal, medical, engineering, scientific, or high-cost decisions, confirm conversions against the applicable official standard or expert reference.