// Converter
Temperature Converter online
Convert between Celsius, Fahrenheit and Kelvin — real-time
by
CHUNKY
MUNSTER
MUNSTER
Type a number into any of the three fields and the other two recalculate instantly. The converter uses the standard formulas C = (F−32) × 5/9 and K = C + 273.15, with results rounded to four decimal places to avoid floating-point noise from the JavaScript engine.
Negative inputs are accepted down to −273.15 °C (0 K) — anything below absolute zero is physically impossible, so values clamp visually but won't crash the page. The reference row beneath the inputs gives the freezing point of water, the boiling point at sea-level standard pressure, and average human body temperature, so you can sanity-check your conversion at a glance.
Multiply the Celsius value by 9/5 and add 32. So 100 °C × 9/5 = 180, plus 32 gives 212 °F. The reverse is (F − 32) × 5/9.
Kelvin is defined so that the triple point of water is exactly 273.16 K. That places absolute zero at −273.15 °C — the extra 0.15 isn't a rounding error, it's part of the SI definition.
Currently only Celsius, Fahrenheit and Kelvin are shown. Rankine equals Fahrenheit + 459.67, and Réaumur equals Celsius × 0.8 if you need to convert manually.
Most cross-scale conversions are non-integer — 100 °F is exactly 37.7778 °C (with rounding). The output is truncated to four decimal places to keep it readable while staying accurate.
Explore the full suite of Converter tools and 290+ other free utilities at Chunky Munster.