Temperature Converter
Convert between Celsius (°C), Fahrenheit (°F), Kelvin (K), Rankine (°R), Réaumur (°Ré), Rømer (°Rø), Newton (°N), and Delisle (°D). Instant, precise, client-side.
Settings
Type in any unit field. All others update instantly. Copy buttons copy the formatted value.
Quick Convert
All Units
Formulas
C = (F - 32) × 5/9C = K - 273.15C = (R × 5/9) - 273.15C = Ré × 5/4C = (Rø - 7.5) × 40/21C = N × 100/33C = 100 - D × 2/3
F = C × 9/5 + 32K = C + 273.15R = (C + 273.15) × 9/5Ré = C × 0.8Rø = C × 21/40 + 7.5N = C × 33/100D = (100 - C) × 3/2
Free Online Temperature Converter
Convert temperatures across Celsius, Fahrenheit, Kelvin, Rankine, Réaumur, Rømer, Newton, and Delisle with instant accuracy. Everything runs locally in your browser for privacy and speed.
How the converter works
The tool uses Celsius as an internal baseline. Your input is converted to Celsius using the exact inverse formula, then mapped to every other unit. You can adjust the decimal precision to control rounding.
When to use each scale
- Celsius (°C) — everyday weather, science outside thermodynamics.
- Fahrenheit (°F) — common in the US for weather and cooking.
- Kelvin (K) — scientific work; absolute zero reference.
- Rankine (°R) — thermodynamics (imperial scale analogue to Kelvin).
- Réaumur (°Ré), Rømer (°Rø), Newton (°N), Delisle (°D) — historical/legacy scales.
Accuracy and rounding
Formulas use standard constants like 273.15 for the Kelvin–Celsius offset. Precision control lets you choose 0–6 decimals. For lab-grade use, keep higher precision; for cooking or HVAC, fewer decimals are usually enough.
FAQ
Is this converter offline?
Yes. No network calls. It works fully in your browser.
What about negative temperatures?
All formulas work for negative values, including sub-zero Celsius and Fahrenheit.
Can I copy results?
Use the copy buttons next to each field or the quick convert output.