How do I convert Celsius to Fahrenheit?

Type your number in the Value field, set From to Celsius and To to Fahrenheit, then press Convert. For example, 25 Celsius shows as 77.00 Fahrenheit. The formula it uses is (C x 9/5) + 32.

Can this converter handle Kelvin?

Yes. Kelvin is one of the three scales in both the From and To dropdowns, so you can go Celsius to Kelvin, Fahrenheit to Kelvin, or back the other way. Water freezes at 273.15 K and boils at 373.15 K.

Does it work for negative temperatures?

It does. Enter a minus sign before the number, like -40, and the converter handles it. A fun fact: -40 reads the same in both Celsius and Fahrenheit.

Is my input sent anywhere?

No. The math runs entirely in your browser with JavaScript, so nothing you type is uploaded or stored. It also works offline once the page has loaded.

Temperature Converter

Value

From

25 °C =

77 °F

What this temperature converter does

This tool turns a temperature from one scale into another: Celsius, Fahrenheit, or Kelvin, in any direction. It is handy for students checking homework, cooks following a recipe written for a different country, travelers reading a foreign weather forecast, and anyone in science or engineering who juggles Kelvin. You pick the two scales, enter a number, and read the answer right away.

How to use it

Type the temperature into the Value box (you can use decimals and negatives, like 98.6 or -10).
Open the From dropdown and choose the scale your number is currently in: Celsius, Fahrenheit, or Kelvin.
Open the To dropdown and pick the scale you want the result in.
Press Convert. The result appears in large text, for example 25 °C = 77.00 °F.
Change any field and convert again to compare other readings.

The Fahrenheit result is rounded to two decimals, which is plenty for cooking, weather, and everyday use.

Why convert here

It is quick. There is no waiting on a server, because the calculation happens on your own device the moment you click. That also keeps it private: the number you enter never leaves your browser, and the page keeps working even if your connection drops.

It is free and open, with no account, no pop-ups, and no daily cap. The conversions follow the standard formulas, so Celsius to Fahrenheit uses (C x 9/5) + 32, and Kelvin offsets Celsius by 273.15. Same answers a textbook would give.

A quick tip

A few anchor points make sanity-checking easy: 0 °C equals 32 °F, body temperature is roughly 37 °C or 98.6 °F, and a comfortable room sits near 21 °C or 70 °F. If a result looks far off from these, double-check which scale you set in the From box.

Frequently asked questions

How do I convert Celsius to Fahrenheit?: Type your number in the Value field, set From to Celsius and To to Fahrenheit, then press Convert. For example, 25 Celsius shows as 77.00 Fahrenheit. The formula it uses is (C x 9/5) + 32.
Can this converter handle Kelvin?: Yes. Kelvin is one of the three scales in both the From and To dropdowns, so you can go Celsius to Kelvin, Fahrenheit to Kelvin, or back the other way. Water freezes at 273.15 K and boils at 373.15 K.
Does it work for negative temperatures?: It does. Enter a minus sign before the number, like -40, and the converter handles it. A fun fact: -40 reads the same in both Celsius and Fahrenheit.
Is my input sent anywhere?: No. The math runs entirely in your browser with JavaScript, so nothing you type is uploaded or stored. It also works offline once the page has loaded.

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Last updated: June 15, 2026