Temperature scales with affine conversion formulas, including modern and historical scales.
All factors come from the central conversion registry.
| Unit | Symbol | System | Definition |
|---|---|---|---|
| Celsius | °C | SI derived | K = °C + 273.15 |
| Fahrenheit | °F | US customary | K = (°F + 459.67) × 5/9 |
| Kelvin | K | SI | K = K |
| Rankine | °R | Engineering | K = °R × 5/9 |
| Réaumur | °Ré | Historical | K = °Ré × 5/4 + 273.15 |
| Rømer | °Rø | Historical | °C = (°Rø − 7.5) × 40/21 |
| Delisle | °De | Historical | °C = 100 − °De × 2/3 |
| Newton Temperature Scale | °N | Historical | °C = °N × 100/33 |
Temperature requires affine formulas rather than a simple multiplier. Celsius and Fahrenheit have different zero points, while Kelvin uses the same interval size as Celsius with absolute zero at 0 K.
The interactive calculator, reference table and indexed pair pages all read from the same conversion registry, so unit definitions and formulas stay synchronized.