Temperature Converter
＋More features: quick reference table and oven setting guide
Build a Celsius / Fahrenheit reference table
Set a start, an end and a step, and a conversion table is built for you.
What should I set my oven to?
Enter the Fahrenheit temperature from your recipe and this gives a setting rounded to 10 °C, which is how most ovens in Japan are marked, plus the equivalent gas mark used in British recipes.
Just type a temperature and you instantly get all three values: Celsius (°C), Fahrenheit (°F) and Kelvin (K). Useful when you want to turn the oven temperature (°F) in an overseas recipe, or a US weather forecast, into the Celsius used everywhere in Japan.
How to use
- Enter the temperature (decimals are fine).
- Choose the unit of the number you entered (°C, °F or K).
- All three units appear below as you type — no button needed.
How it is calculated
- Fahrenheit (°F) = Celsius (°C) × 1.8 + 32
- Kelvin (K) = Celsius (°C) + 273.15
- Example: an oven at 350 °F is (350 − 32) ÷ 1.8 = about 177 °C
- Nothing can be colder than absolute zero (−273.15 °C = −459.67 °F = 0 K), so lower values return an error.
Sources and assumptions
- The relation between Celsius and Kelvin (t/°C = T/K − 273.15) comes from the definition in the International System of Units (SI): National Metrology Institute of Japan (AIST), “The International System of Units (SI), 9th edition” (in Japanese)
- The Fahrenheit conversion (°F = °C × 9/5 + 32) is arithmetic based on the definition of the unit.
Assumptions and notes
- Values are rounded to two decimal places.
- Fahrenheit is used mainly in the United States. “100 degrees Fahrenheit” is about 37.8 °C, the kind of temperature Japan calls a midsummer day.
Frequently asked questions
What is 350 °F (oven) in Celsius?
About 177 °C. The temperatures you see most often in overseas recipes are 325 °F ≈ 163 °C, 350 °F ≈ 177 °C, 375 °F ≈ 191 °C and 400 °F ≈ 204 °C. On an oven in Japan, most of these recipes end up set at around 180 °C.
Is there a temperature where Fahrenheit and Celsius are the same number?
Yes, −40 degrees: −40 °C = −40 °F. Setting F = C in the formula F = 1.8C + 32 gives C = −40.
When is Kelvin used?
It is the unit of absolute temperature used in physics and chemistry (the ideal gas law, for example). Its lower limit is 0 K (absolute zero) = −273.15 °C, so there are no negative values. One kelvin is the same size as one degree Celsius.