Temperature Converter

Celsius, Fahrenheit, and Kelvin formulas

Unlike length or weight, temperature scales have different zero points, so you can't just multiply. The conversion goes through Celsius as the bridge:

• °F → °C: (°F − 32) × 5⁄9
• K → °C: K − 273.15
• °C → °F: °C × 9⁄5 + 32
• °C → K: °C + 273.15

Some quick reference points: water freezes at 0°C / 32°F / 273.15 K; water boils (at 1 atm) at 100°C / 212°F / 373.15 K; absolute zero is 0 K / −273.15°C / −459.67°F.

For unit ratios that are a simple multiplication (length, weight, volume, area), see the unit converter.

Limitations: this converter handles temperature scales only. It does not adjust for altitude, pressure, weather station calibration, or scientific measurement uncertainty.

Last reviewed: 2026-05-14. The formulas are the standard Celsius/Fahrenheit/Kelvin relationships and run locally in your browser.

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Frequently asked questions

Why is temperature not converted with a simple multiplier?

Celsius, Fahrenheit, and Kelvin have different zero points. Fahrenheit also uses a different interval size, so most conversions need both multiplication and addition or subtraction.

Can Kelvin be negative?

No. Kelvin starts at absolute zero. This tool still shows the math for any numeric input, but negative Kelvin values are not physically meaningful.

Are the results exact?

The formulas are exact for scale conversion, but the displayed result is rounded to four decimal places for readability.