Temperature Converter

Temperature is the odd one out among conversions. Every other unit on this site converts by multiplying: a mile is a fixed number of metres, and zero is zero on both scales. Temperature scales do not share a zero point, so each conversion needs an offset as well as a ratio — which is exactly why so many quick mental shortcuts get it wrong.

The rough shortcut most people use — double it and add 30 — is fine for weather and badly wrong for cooking. At 180 °C the shortcut says 390 °F; the real answer is 356 °F. That is the difference between a baked cake and a burnt one.

Amount

From

1 Celsius = 33.8 Fahrenheit

Converted in your browser. Nothing is sent anywhere.

This page’s converter uses ordinary JavaScript numbers, so long results round like any web calculator. CalcBoard’s in-app converter uses exact decimal arithmetic and works with no connection at all.

Common temperature conversions

Common temperature conversions for 1, 5 and 100 units
Conversion	1	5	100
Celsius → Fahrenheit	33.8	41	212
Fahrenheit → Celsius	-17.222222	-15	37.777778
Celsius → Kelvin	274.15	278.15	373.15
Kelvin → Celsius	-272.15	-268.15	-173.15

The formulas

Temperature is the one category that is not a simple multiplication, because the scales do not share a zero point. Each conversion needs an offset as well as a ratio:

Celsius to Fahrenheit: °F = °C × 9/5 + 32
Fahrenheit to Celsius: °C = (°F − 32) × 5/9
Celsius to Kelvin: K = °C + 273.15
Kelvin to Celsius: °C = K − 273.15
Fahrenheit to Kelvin: K = (°F + 459.67) × 5/9

−40 is the one temperature where Celsius and Fahrenheit agree, which makes it a useful sanity check on any converter, including this one.

Convert without a browser

This page needs a connection. The CalcBoard app does the same conversions offline, with exact decimal arithmetic, and puts the converter next to a working calculator — so you can convert a measurement in one panel and immediately use it in a formula in the next, without copying anything by hand.

Free vs. Premium, honestly: the free app includes 2 panels, basic mode, 3 converter categories, and your last 10 history entries — no ads, no time limits. A one-time $2.99 purchase (no subscription) unlocks scientific and programmer modes, up to 8 panels, the shared value tray, all 10 converter categories, full history with search and CSV export, and all themes and button styles.

Frequently Asked Questions

What is the formula for Celsius to Fahrenheit?

°F = °C × 9/5 + 32. Going the other way, °C = (°F − 32) × 5/9. The multiplication and the offset both matter — skipping the 32 is the most common mistake.

At what temperature are Celsius and Fahrenheit the same?

−40. That is the only point where the two scales cross, which makes it a quick way to sanity-check any temperature converter.

Why is Kelvin not written with a degree sign?

Kelvin is an absolute scale measured from absolute zero, so it is written as 'K', not '°K'. To convert, add 273.15 to Celsius. Room temperature of 20 °C is 293.15 K.

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