Convert between Fahrenheit, Celsius, and Kelvin instantly. Free temperature calculator with formulas, reference points, and bidirectional conversion.
Convert temperatures between Fahrenheit, Celsius, and Kelvin with this all-in-one tool. Enter a value in any scale and see all three equivalents instantly.
Temperature conversion is needed constantly: interpreting weather forecasts from other countries, setting oven temperatures from international recipes, understanding scientific data, and working with engineering specifications that use different scales.
The three scales serve different purposes. Fahrenheit is used for weather and cooking in the US. Celsius is the international standard for everyday temperature and most science. Kelvin is the SI unit used in physics, chemistry, and engineering where absolute zero matters.
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This structured approach transforms vague productivity goals into measurable targets, making it easier to track improvement and stay motivated toward meaningful professional achievements.
Weather, cooking, science, and medicine all use different temperature scales. This converter handles all three scales instantly, eliminating the need to remember different formulas. Regular monitoring of this value helps individuals and teams detect productivity patterns and adjust workflows before small inefficiencies become entrenched and hard to correct. Having accurate figures readily available simplifies project planning, deadline negotiation, and workload balancing conversations with managers, clients, and team members.
°C = (°F − 32) × 5/9 °F = °C × 9/5 + 32 K = °C + 273.15 °C = K − 273.15 K = (°F − 32) × 5/9 + 273.15
Result: 22.22°C / 295.37 K
°C = (72 − 32) × 5/9 = 40 × 0.5556 = 22.22°C. Kelvin = 22.22 + 273.15 = 295.37 K. This is a comfortable room temperature.
Daniel Fahrenheit created his scale in 1724, using brine (salt water) as 0° and body temperature as roughly 96° (later adjusted). Anders Celsius proposed his centigrade scale in 1742, initially inverted (100° for freezing, 0° for boiling), which was later reversed. Lord Kelvin introduced the absolute scale in 1848 for thermodynamics.
Water freezes at 32°F/0°C, room temperature is about 72°F/22°C, body temperature is 98.6°F/37°C, water boils at 212°F/100°C. For cooking: 350°F = 177°C (moderate oven), 450°F = 232°C (hot oven).
Kelvin is the SI unit for thermodynamic temperature. Many physics equations require Kelvin because they involve ratios or differences relative to absolute zero. The Kelvin scale was redefined in 2019 in terms of the Boltzmann constant.
Subtract 32 from the Fahrenheit value, then multiply by 5/9 (or divide by 1.8). For example: 72°F → (72 − 32) × 5/9 = 22.2°C. This formula works for any temperature value.
Celsius and Kelvin have the same degree size (1°C = 1 K), but different zero points. 0°C = 273.15 K. Kelvin starts at absolute zero (the coldest possible temperature), while Celsius uses water's freezing point as zero.
Absolute zero is 0 Kelvin = −273.15°C = −459.67°F. It is the theoretical lowest possible temperature where all molecular motion ceases. It has been approached in labs but never reached.
The Fahrenheit scale was widely adopted in English-speaking countries before Celsius became the scientific and international standard. The US never switched, partly due to the cost and disruption of changing thermometers, weather systems, and public familiarity.
Room temperature is typically 68–72°F (20–22°C / 293–295 K). In science, "standard temperature" is defined as 25°C (77°F / 298.15 K) or sometimes 20°C depending on the standard used.
Fahrenheit and Celsius read the same value at −40°. This is the unique intersection point: −40°F = −40°C. You can verify: (−40 − 32) × 5/9 = −72 × 5/9 = −40.