Temperature Converter - Celsius, Fahrenheit, Kelvin

Celsius, Fahrenheit, and Kelvin Explained

The Celsius scale, used by nearly every country in the world, pins 0 degrees to the freezing point of water and 100 degrees to its boiling point at sea level. Fahrenheit, still standard in the United States, puts those same two points at 32 and 212 degrees, which is why the conversion needs both a multiplication (9/5) and an offset (+32). Kelvin is the scientific scale: it uses the same step size as Celsius but starts at absolute zero, the temperature at which molecular motion reaches its minimum, so 0 K equals -273.15 C and nothing can be colder.

A few anchors make mental conversion easier. The scales cross at -40, the one temperature where Celsius and Fahrenheit agree. Room temperature is about 21 C or 70 F. Body temperature is 37 C or 98.6 F, and a fever above 38 C (100.4 F) is the common medical threshold. For a quick estimate from Celsius to Fahrenheit, double the number and add 30: it turns 20 C into an estimated 70 F versus the true 68 F, and stays within a couple of degrees for everyday weather.

Cooking is where most people meet the conversion in practice. American recipes bake at 350 F, which is 177 C, usually rounded to 180 C on European ovens. A hot 450 F oven for pizza or bread is about 230 C. Gas mark 4 equals 180 C or 350 F. If a recipe seems wildly off, check whether it assumes a fan (convection) oven: convention is to reduce a conventional-oven temperature by about 20 C (roughly 25-30 F) when using the fan.

The converter recalculates from whichever field you type in, flags anything below absolute zero as impossible, and rounds to two decimals. For related conversions, ToolForte also offers a general Unit Converter for length, weight, and volume, plus a Cooking Measurement Converter for cups, grams, and milliliters. Everything runs free in your browser.