Temperature Converter
Turn any temperature into a different scale — Celsius, Fahrenheit, or Kelvin — using exact, offset-based formulas.
Offset-based
Temperature scales differ in both degree size and zero point, so the converter shifts and scales — never just multiplies.
Display rounding
Results are shown to four decimal places, so some conversions may round the last digit.
What is a temperature converter?
One value, any scale
A temperature converter changes a reading from one scale into another — Celsius to Fahrenheit, Fahrenheit to Celsius, Celsius to Kelvin, and back. It works by translating every value through a single shared pivot, the Celsius scale, so any pair of scales can be converted with one consistent rule. This tool covers the three scales used in daily life, science, and engineering: Celsius (°C), Fahrenheit (°F), and Kelvin (K). It is handy for cooking, weather, travel between countries that use different scales, schoolwork, and lab work.
Unlike length or weight, temperature scales do not share a zero point, so converting means both scaling the degree size and shifting the zero.
°F = °C × 9⁄5 + 32To reach Kelvin, only the zero point moves, because a Kelvin degree is the same size as a Celsius degree: K = °C + 273.15. The converter pivots every value through Celsius — it first turns your input into Celsius, then into the scale you want — so a single pair of rules handles every direction, including Fahrenheit straight to Kelvin.
Suppose you want to convert 100 °C into Fahrenheit.
Scale the degree size
Multiply by 9⁄5: 100 × 9 ÷ 5 = 180.Shift the zero point
Add 32 to line up the scales: 180 + 32 = 212.Read the result
100 °C converts to 212 °F — the boiling point of water at sea level.
Temperature conversion is affine — an offset conversion, not a ratio — which is why 0 °C is not 0 °F but 32 °F, and why doubling the Celsius reading does not double the Fahrenheit reading. Each scale anchors its zero differently: Celsius at the freezing point of water, Fahrenheit 32 degrees below that, and Kelvin at absolute zero, the coldest temperature physically possible, which is −273.15 °C = 0 K. The Celsius and Fahrenheit scales cross at exactly −40°, where −40 °C equals −40 °F. For everyday use, round the result to a sensible number of decimals; for scientific work, keep the full precision shown.
The arithmetic is exact; the limits are physical and display-related.
Absolute zero and rounding
Kelvin cannot go below 0, since 0 K is absolute zero — a Celsius value under −273.15 or a Fahrenheit value under −459.67 has no physical meaning, though the formula will still return a number. Results are rounded to four decimal places, so conversions with long decimal tails may lose the last digit. This converter handles temperature points only; it does not convert temperature differences or rates, which use the degree-size scaling without the zero-point shift.