Using the model
Symbols, assumptions and limitations
SI definitions and exact physical constants are used where applicable. Mass, pressure, and length are treated as non-negative magnitudes; signed values are accepted for temperature and energy. Displayed values are rounded, not the internal calculation.
Worked examples
See the method in practice
Energy example
1 electron volt equals 1.602176634 × 10⁻¹⁹ joules exactly.
Pressure example
1 standard atmosphere equals 101,325 pascals.
Questions
Frequently asked
Why is temperature conversion different?
Temperature scales have different zero points, so conversion requires an offset as well as a scale factor.
Are conversions rounded?
Calculations retain JavaScript floating-point precision; only the visible result is formatted.
Sources & review
Equations and examples are checked against the references below. Results are educational and should be independently verified for safety-critical work.
NIST SI unitsWritten by the STEM Hub editorial team · Reviewed August 11, 2026 · Review methodology