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Temperature Converter

Convert between Celsius, Fahrenheit, Kelvin, Rankine, and Réaumur — the five temperature scales in common scientific and everyday use.

Results from this calculator are estimates provided for general informational purposes only, based on formulas, rates, and standards commonly accepted as of 2026. Figures may differ slightly from other calculators or professional sources due to rounding methods, differing assumptions, or regional regulations, and rules may change over time. Always consult a qualified professional — such as a financial advisor, healthcare provider, or other relevant specialist — before making decisions based on these results.

The numeric value you want to convert. Decimals are accepted.

Result

Water's freezing and boiling points, for reference

Freezing point

0°C / 32°F

Boiling point

100°C / 212°F

What is a Temperature Converter?

A temperature converter translates a reading from one temperature scale into its equivalent on another. Unlike length or weight, temperature scales are not simple multiples of each other — each has its own zero point, so converting between them requires an offset as well as a scaling factor (an "affine" formula, not a plain ratio).

All conversions below route through Celsius as a common reference point, using each scale's exact defining relationship to it.

Conversion chart: Celsius to Fahrenheit

Conversion table

Celsius (°C) Fahrenheit (°F)
0.01 °C 32.018 °F
0.1 °C 32.18 °F
1 °C 33.8 °F
2 °C 35.6 °F
3 °C 37.4 °F
5 °C 41 °F
10 °C 50 °F
20 °C 68 °F
50 °C 122 °F
100 °C 212 °F
1000 °C 1832 °F

Supported Scales

Scale Symbol Water Freezes Water Boils
Celsius °C 0°C 100°C
Fahrenheit °F 32°F 212°F
Kelvin K 273.15K 373.15K
Rankine °R 491.67°R 671.67°R
Réaumur °Ré 0°Ré 80°Ré

About These Parameters

Value
The temperature reading you want to convert, in the "From" scale. Negative values are accepted.
From Unit
The scale your input value is currently measured in.
To Unit
The scale you want the result converted into. Use the swap button to flip From and To instantly.

How Temperature Conversion Works

The Formula

Because each scale has a different zero point, conversion needs both a scale factor and an offset, not just a multiplier. The three most common formulas:

°F = °C × 9/5 + 32
K  = °C + 273.15
°C = (°F − 32) × 5/9

For Celsius → Fahrenheit: 100°C converts to 212°F. Every conversion on this page routes through Celsius internally, then applies the target scale's own offset and factor.

Why Temperature Isn't a Simple Ratio

Length and weight conversions are pure multiplications because both scales share the same zero point (nothing weighs "negative zero"). Temperature scales don't: 0°C is water's freezing point, not the absence of heat, so "twice as hot" in Celsius doesn't mean "twice as hot" in Fahrenheit. Only Kelvin and Rankine start at true absolute zero, which is why they're used for scientific calculations involving ratios of temperature.

Absolute Zero

Absolute zero — 0 K, −273.15°C, −459.67°F, 0°R — is the coldest possible temperature, the point at which atoms have minimum possible thermal motion. It has never been reached experimentally, though physicists have cooled matter to within a fraction of a billionth of a degree above it.

Example

100°C equals 212°F. For comparison, normal human body temperature (37°C) is 98.6°F — this value is 113.4°F warmer than body temperature.

Frequently Asked Questions

Why does the US use Fahrenheit while most of the world uses Celsius?

The US inherited Fahrenheit from British colonial-era usage and never mandated a switch to Celsius, unlike the UK and most other countries, which adopted Celsius alongside broader metrication in the mid-20th century.

What's the difference between Kelvin and Celsius?

They use the same size degree — a 1 K change equals a 1°C change — but Kelvin starts at absolute zero (0 K = −273.15°C) instead of water's freezing point, so Kelvin values are never negative.

Is the Réaumur scale still used anywhere?

Rarely. It was common in 18th and 19th century Europe but was almost entirely replaced by Celsius; it occasionally survives in older European recipes, particularly some traditional cheese-making and confectionery instructions.

Possible Temperature Conversions

See also