Temperature Converter
Enter a value to instantly convert between temperature units.
Temperature conversion is unavoidable for anyone dealing with international recipes, weather reports, or scientific data — a US oven dial reads in Fahrenheit while most of the world's recipes and weather forecasts use Celsius, and scientific work often requires Kelvin. Unlike most conversions on this site, temperature scales don't share a common zero point, which means temperature conversions involve addition and subtraction as well as multiplication — a detail that trips up more people than almost any other conversion type.
1 Celsius = 33.8 Fahrenheit
Key Formulas
Celsius → Fahrenheit
°F = f(°C)Fahrenheit → Celsius
°C = f(°F)Celsius → Kelvin
K = f(°C)Kelvin → Celsius
°C = f(K)Popular Conversions
All Temperature Conversions
About Temperature Conversions
History & Background
The Celsius scale, devised by Anders Celsius in 1742, originally placed 0° at the boiling point of water and 100° at freezing — the reverse of today's scale, which was inverted shortly after his death. Daniel Fahrenheit's scale, created around 1724, was based on a mixture of brine (defining 0°) and (in some accounts) the average human body temperature, producing the now-familiar 32°F freezing and 212°F boiling points for water. The Kelvin scale, introduced by Lord Kelvin in 1848, is the SI base unit for temperature and starts at absolute zero — the theoretical point at which all thermal motion stops — making it essential for scientific work where negative temperatures would be physically meaningless.
How to Use This Converter
Enter a temperature in your starting scale and the converter will calculate the equivalent in your target scale instantly. Because temperature conversions involve an offset (not just a multiplication factor), the formulas differ from every other category on this site — for example, °F = (°C × 9/5) + 32, not simply °C × a constant. Each conversion page shows the exact formula used.
Frequently Asked Questions
Why can't I just multiply to convert Celsius to Fahrenheit?
Because the two scales have different zero points as well as different step sizes. 0°C is 32°F, not 0°F — so the conversion requires both scaling (multiplying by 9/5) and shifting (adding 32). This combination of scaling and shifting is called an 'affine' transformation, and it's the reason temperature conversions can't use the simple base-unit multiplication formula used for length, weight, or volume.
What is absolute zero and why does Kelvin start there?
Absolute zero (0 K, equal to -273.15°C or -459.67°F) is the theoretical temperature at which particles have minimal thermal motion — it's the lowest temperature physically possible. The Kelvin scale starts at this point specifically so that temperature values are always positive and proportional to the actual thermal energy present, which is essential for physics and chemistry calculations like the gas laws.
Is a 1-degree change the same size in Celsius and Fahrenheit?
No — a 1°C change equals a 1.8°F change (since the Fahrenheit scale has 180 degrees between freezing and boiling water, versus 100 for Celsius). Kelvin and Celsius do share the same degree size (a 1°C change equals a 1K change), which is why converting between them is just a matter of adding or subtracting 273.15, with no multiplication needed.
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