Temperature Converter: Celsius, Fahrenheit, Kelvin, Rankine and historical scales
Scientific conversion tool across 8 temperature scales: Celsius (°C), Fahrenheit (°F), Kelvin (K), Rankine (°R), Réaumur (°Ré), Delisle (°De), Newton (°N) and Rømer (°Rø). Supports absolute mode (temperature values) and delta mode (temperature differences).
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When to use this tool
Quick conversion across scales in physics, chemistry, biology and geosciences: lab work (incubations, PCR), thermodynamics (Δ°C ↔ ΔK ↔ Δ°F for heat capacities and coefficients), industrial processes using imperial scales (°F, °R), cryogenics (Kelvin) and comparison with historical scales (Réaumur, Newton).
How it works
Enter a value and pick the source and target scales. The engine uses Kelvin as the canonical hub: it converts the input to K, then from K to the target scale. The widget displays the substituted formula applied for each conversion, plus an equivalents panel listing the value in all 8 scales simultaneously. The 'Δ Difference' toggle switches to temperature-difference mode, where only the scale factor applies (no offsets): Δ°C = ΔK, but Δ°F = (5/9) × Δ°C. In absolute mode, values below the source scale's absolute zero trigger a warning.