Temperature Converter — Free Online Temperature Unit Converter
Our free temperature converter instantly converts between all major temperature scales. Use the temperature converter to switch between Celsius, Fahrenheit, Kelvin, Rankine, and Réaumur — no sign-up required. This temperature converter uses exact, internationally verified formulas for every scale pair. Learn more at Wikipedia's temperature scale conversion reference and the NIST unit conversion guide.
🌡️ Temperature Converter
Quick Reference Tables
Common temperature values converted at a glance.
Celsius → Fahrenheit
| Celsius (°C) | Fahrenheit (°F) |
|---|---|
| 0.5 °C | 32.9 °F |
| 1 °C | 33.8 °F |
| 2 °C | 35.6 °F |
| 3 °C | 37.4 °F |
| 5 °C | 41 °F |
| 10 °C | 50 °F |
| 15 °C | 59 °F |
| 20 °C | 68 °F |
| 25 °C | 77 °F |
| 50 °C | 122 °F |
Fahrenheit → Celsius
| Fahrenheit (°F) | Celsius (°C) |
|---|---|
| 0.5 °F | -17.5 °C |
| 1 °F | -17.222222 °C |
| 2 °F | -16.666667 °C |
| 3 °F | -16.111111 °C |
| 5 °F | -15 °C |
| 10 °F | -12.222222 °C |
| 15 °F | -9.444444 °C |
| 20 °F | -6.666667 °C |
| 25 °F | -3.888889 °C |
| 50 °F | 10 °C |
Celsius → Kelvin
| Celsius (°C) | Kelvin (K) |
|---|---|
| 0.5 °C | 273.65 K |
| 1 °C | 274.15 K |
| 2 °C | 275.15 K |
| 3 °C | 276.15 K |
| 5 °C | 278.15 K |
| 10 °C | 283.15 K |
| 15 °C | 288.15 K |
| 20 °C | 293.15 K |
| 25 °C | 298.15 K |
| 50 °C | 323.15 K |
Conversion Formulas
The exact math behind every temperature scale conversion.
Understanding Temperature Scales
Celsius vs Fahrenheit — Everyday Use
Celsius (°C) is the standard temperature scale used in science and by most of the world for daily weather, cooking, and medicine. Water freezes at 0 °C and boils at 100 °C at sea level.
Fahrenheit (°F) is primarily used in the United States. Water freezes at 32 °F and boils at 212 °F. Body temperature is approximately 98.6 °F (37 °C). The Celsius to Fahrenheit conversion is one of the most searched globally.
Kelvin — The Scientific Standard
Kelvin (K) is the SI base unit for thermodynamic temperature. Unlike Celsius and Fahrenheit, it has no negative values — 0 K is absolute zero, the coldest possible temperature in the universe, equivalent to −273.15 °C.
Kelvin is used universally in physics, chemistry, and astronomy. The Celsius to Kelvin conversion is simply adding 273.15 — making it the simplest temperature formula of all.
Rankine & Réaumur — Rare But Supported
Rankine (°R) is the Fahrenheit equivalent of Kelvin — an absolute thermodynamic scale starting at absolute zero, used in some engineering fields in the United States. 0 °R = 0 K = −459.67 °F.
Réaumur (°Ré) is a historical scale once widely used in Europe, where water freezes at 0 °Ré and boils at 80 °Ré. Though largely obsolete, ConvertNow fully supports it for historical and scientific reference.
Why Temperature Conversions Are Unique
Unlike most unit conversions — which are simple multiplication — temperature scales have different zero points (offsets) and different step sizes (factors). This means you cannot convert Celsius to Fahrenheit with a single multiplication.
For example: °F = (°C × 9/5) + 32. Our converter handles all the offset arithmetic automatically and instantly, so you always get a precise result regardless of which pair of scales you choose.
Frequently Asked Questions
Frequently Asked Questions
1 Celsius (°C) equals 33.8 Fahrenheits (°F).
Multiply the value in Celsiuss by 33.8. For example, 10 Celsiuss = 50 Fahrenheits.
Yes. ConvertNow uses precise factors for all unit calculations. Currency conversions use live exchange rates updated regularly.
Yes — type into the right-hand field to reverse the conversion.