Temperature Converter
Convert Celsius, Fahrenheit, and Kelvin instantly
Temperature Converter tool
Quick Presets
Common Temperature Reference Points
| Description | °C | °F | K |
|---|---|---|---|
| Absolute Zero | -273.15 | -459.67 | 0 |
| Dry Ice (CO₂) | -78.5 | -109.3 | 194.65 |
| Frozen Food Storage | -18 | -0.4 | 255.15 |
| Water Freezing | 0 | 32 | 273.15 |
| Refrigerator | 4 | 39.2 | 277.15 |
| Room Temperature | 20 | 68 | 293.15 |
| Human Body Temp | 37 | 98.6 | 310.15 |
| Pasteurization | 72 | 161.6 | 345.15 |
| Water Boiling | 100 | 212 | 373.15 |
| Oven (Moderate) | 175 | 347 | 448.15 |
Temperature Converter: key facts
- What it does
- Convert Celsius, Fahrenheit, and Kelvin instantly
- Category
- Converters
- Cost
- Free, with no account, sign-up, or install.
- Your data
- Runs entirely in your browser — the files and text you enter are never uploaded to a server.
- Last reviewed
- . Report an incorrect result.
Understanding the Temperature Converter
Celsius and Fahrenheit coexist in daily life in a way almost no other unit pair does — weather apps switch between them depending on where you are, recipes cross the Atlantic, and scientific contexts demand Kelvin. Converting between them by memory (multiply by 9/5, add 32, subtract 32, multiply by 5/9) is doable but error-prone, especially for Kelvin where the offset is 273.15.
Cooks converting a European recipe to a US oven temperature, travelers checking the forecast in an unfamiliar country, students working through a chemistry problem in Kelvin, and lab technicians standardizing readings across instruments all run into the same friction. The preset buttons for Absolute Zero, Freezing, Room Temperature, Body Temperature, and Boiling Point are shortcuts for the reference values people look up most often — type a Celsius value and instantly see Fahrenheit and Kelvin, or tap a preset to verify you remember the equivalent correctly.
The companion table shows a dozen common reference temperatures in all three scales side by side. It is the kind of quick-glance chart that used to hang on a refrigerator door — now searchable and always current.
Getting a result
- Type a value in the Celsius, Fahrenheit, or Kelvin field — any of the three updates the other two immediately.
- Or click a quick-preset button (Absolute Zero, Freezing, Room Temp, Body Temp, Boiling) to jump to a standard reference point.
- Use the Copy button next to any field to copy that value to your clipboard.
- Refer to the reference table below for a quick overview of common temperatures in all three scales.
Three scales, converted through Celsius
Every conversion routes through Celsius as the intermediate, which keeps the arithmetic to two formulas per direction rather than a rule for every pair. Fahrenheit uses the nine-fifths ratio and a 32-degree offset; Kelvin is a pure offset of 273.15 with no scaling, because it shares Celsius's degree size.
That difference matters. Celsius and Kelvin degrees are the same size, so a temperature *difference* of 10 degrees is identical in both — only absolute values need the offset. Fahrenheit degrees are five-ninths the size, so differences must be scaled as well as offset, which is the usual source of error when converting a temperature range rather than a temperature.
Results are trimmed to four decimal places, which is well beyond the precision of any everyday measurement.
- 0 °C is 32 °F and 273.15 K — the freezing point of water at standard pressure.
- −40 is the single point where Celsius and Fahrenheit coincide.
- A 10-degree rise in Celsius is a 10 K rise but an 18 °F rise, because the degree sizes differ.
Reasons to use it here
- Instant three-way sync means editing any one field automatically updates both others — no clicking Convert.
- Preset buttons for the five most-referenced temperatures (Absolute Zero through Boiling) save typing when you need a quick sanity check.
- The reference table presents twelve real-world temperature landmarks in all three scales for at-a-glance comparison.
- All conversions use exact formulas (F = C × 9/5 + 32; K = C + 273.15) with no rounding until display, so results are accurate to multiple decimal places.
Why three scales still exist
Kelvin is the SI base unit and starts at absolute zero, the point where thermal motion is minimal — which is why it has no negative values and why it is used throughout physics and chemistry. Its degree size was chosen to match Celsius so that scientific and everyday figures interconvert trivially.
Celsius is anchored to water's freezing and boiling points at standard pressure, which makes it intuitive for weather and cooking. Fahrenheit's anchors were more arbitrary, and it survives in general use mainly in the United States. Its finer degrees are a genuine if minor advantage for describing air temperature without decimals.
Two notes worth carrying. Kelvin takes no degree symbol — it is written 273 K, not 273 °K — and absolute zero at −273.15 °C is a lower bound that cannot be reached, only approached. Rankine, an absolute scale with Fahrenheit-sized degrees, still appears occasionally in American engineering.
Frequently Asked Questions
What is the formula to convert Celsius to Fahrenheit?
F = C × 9/5 + 32. For example, 100°C (boiling water) is 100 × 9/5 + 32 = 212°F. To convert Fahrenheit back to Celsius: C = (F − 32) × 5/9.
What is Absolute Zero and why does it matter?
Absolute Zero is the lowest theoretically possible temperature: −273.15°C, −459.67°F, or 0 K. It is the point where particles have minimum thermal energy. Kelvin is measured from this point, which is why 0 K equals −273.15°C, and scientific calculations in thermodynamics and chemistry often use Kelvin.
What is normal body temperature in Fahrenheit?
The classic figure is 98.6°F (37°C / 310.15 K), derived from a 19th-century German study. Modern research shows average body temperature is closer to 97.9°F (36.6°C), and it varies by individual, time of day, and measurement method.
Why does Kelvin not use a degree symbol?
Kelvin is an absolute thermodynamic scale, not a relative "degree" scale. The SI system officially dropped the degree symbol for Kelvin in 1967 to reflect this — you write 373.15 K, not 373.15°K.
