Enter Temperature & Units
Result
Converted: –
Formula: –
🌡️ Overview: Convert Any Temperature Scale
The Temperature Unit Converter lets you easily switch between major and historical temperature units such as Celsius, Fahrenheit, Kelvin, Rankine, Delisle, Newton, Réaumur, Rømer, and Gas Mark. Whether you're a scientist, chef, engineer, or just curious, this tool ensures consistent, mathematically precise conversions.
Most scientific conversions pivot through the Kelvin (K) scale—an absolute temperature reference based on thermodynamic zero. This makes it a reliable intermediary when switching between linear and offset-based scales.
- Linear Scales: Celsius, Kelvin, Rankine
- Offset Scales: Fahrenheit, Delisle, Newton, Réaumur, Rømer
- Categorical/Oven Scale: Gas Mark (used in UK baking)
🧮 Formula & Methodology
All temperature conversions go through the Kelvin scale:
TK = ftoK(Tin) Tout = ffromK(TK)
Conversion formulas per scale:
| Scale | Symbol | To Kelvin | From Kelvin |
|---|---|---|---|
| Celsius | °C | T + 273.15 | T − 273.15 |
| Fahrenheit | °F | (T + 459.67) × 5⁄9 | T × 9⁄5 − 459.67 |
| Kelvin | K | T | T |
| Rankine | °R | T × 5⁄9 | T × 9⁄5 |
| Delisle | °De | 373.15 − 2T⁄3 | (373.15 − T) × 3⁄2 |
| Newton | °N | T × 100⁄33 + 273.15 | (T − 273.15) × 33⁄100 |
| Réaumur | °Ré | T × 5⁄4 + 273.15 | (T − 273.15) × 4⁄5 |
| Rømer | °Rø | (T − 7.5) × 40⁄21 + 273.15 | (T − 273.15) × 21⁄40 + 7.5 |
| Gas Mark | GM | (T × 125⁄9) + 394.26 | (T − 250) ÷ 25 |
📊 Example Conversions
- 100 °C → °F: 100 × 9⁄5 + 32 = 212 °F
- 32 °F → K: (32 + 459.67) × 5⁄9 ≈ 273.15 K
- 20 °De → °C: (373.15 − 20 × 2⁄3) − 273.15 ≈ −6.33 °C
- Gas Mark 6 → °C: GM 6 × 14 = ≈ 200 °C (approximate)
🔍 Use Cases & Applications
- Cooking: Convert Gas Mark to °F or °C for oven settings in international recipes.
- Science & Engineering: Standardize measurements to Kelvin in thermodynamics and simulations.
- Education: Compare historical and modern temperature scales for physics teaching.
- Climate Research: Switch between Celsius and Kelvin in environmental modeling.
- Historical Conversion: Convert legacy lab records (e.g., Newton or Rømer) into modern units.
❓ Frequently Asked Questions
What is the Gas Mark system?
Gas Mark is used in the UK and Ireland for oven temperatures. It ranges roughly from 135 °F (GM 1) to 475 °F (GM 9).
Why is Kelvin used as the base for conversions?
Kelvin is the absolute thermodynamic scale. Using it ensures accurate and standardized conversions, especially for offset-based units.
Are these formulas scientifically accurate?
Yes. All conversion formulas are based on official definitions from the International Temperature Scale of 1990 (ITS-90).
What is the difference between Rankine and Kelvin?
Both are absolute scales. Rankine is to Fahrenheit what Kelvin is to Celsius. Rankine = Fahrenheit + 459.67, then scaled by 5⁄9.
How is Delisle still relevant?
Though obsolete, Delisle is used in historical research and occasionally in Russian sources. This tool preserves backward compatibility.
Can I use this tool for sensor calibration?
Yes. When converting between °C, °F, and K, this tool is precise enough for general sensor calibration and thermal modeling.
Why are so many scales obsolete?
Historical contexts, regional standards, and differing definitions of "zero" led to many competing scales before international unification.