Temperature Converter
ℹ How it works
Conversions use the exact defining formulas — °F = °C × 9/5 + 32 and K = °C + 273.15 — with no rounded factors, so results are precise to the two decimals shown. Kelvin is the SI base unit for temperature: its scale starts at absolute zero, which is why it carries no degree sign and can never be negative. Inputs below −273.15 °C are physically impossible and are clamped automatically. The slider spans absolute zero to 5000 °C with the finest resolution in the everyday range, and everything runs locally in your browser.
Temperature Converter
20 °C →
68.00 °FFAQ
- How do I convert Celsius to Fahrenheit?
- Multiply by 9/5 and add 32: °F = °C × 9/5 + 32. Going the other way, subtract 32 first and then multiply by 5/9: °C = (°F − 32) × 5/9. The two scales cross at −40, the only temperature where both show the same number.
- What is absolute zero?
- Absolute zero is −273.15 °C, −459.67 °F or 0 K — the point where the thermal motion of particles is at its minimum, so no lower temperature exists. That is why this converter clamps any colder input, and why the Kelvin scale, which starts there, has no negative values.
- What do the background colors of the result mean?
- The result panel follows the colors we intuitively associate with temperature. At absolute zero it turns black, like empty space. Deep cold appears as dark navy, passing through ice blue to the blue-white of snow around the freezing point. Room temperature is a neutral white. Above that, the color shifts from a soft orange to red-orange at boiling — and then follows real glowing matter: metal glows orange near 1000 °C, and around 5000 °C the hue approaches the white-yellow of the Sun's surface.
- Who uses Fahrenheit, and what is Kelvin for?
- Fahrenheit is the everyday scale in the United States and a few other places such as the Cayman Islands, Belize and Liberia; almost everywhere else uses Celsius. Kelvin is the SI unit used in science and engineering: because its scale starts at absolute zero, ratios between temperatures are physically meaningful.