Temperature Converter
The Temperature Converter converts between Celsius, Fahrenheit, and Kelvin using exact conversion formulas, with a built-in check to prevent temperatures below absolute zero. Temperature conversions between Celsius and Fahrenheit aren't a simple multiplication because the two scales place zero at different physical points — 0°C is water's freezing point, while 0°F was set from a historical brine-mixture reference roughly 32 Fahrenheit degrees colder. That mismatch means the formula needs both a scale factor (9/5) and an offset (+32); Kelvin, by contrast, uses the same-sized degree as Celsius, so converting between them is addition only (K = °C + 273.15), with no multiplication needed.
How This Tool Works
Enter a temperature value and choose your source and target scale for an instant conversion.
Formula & Method
°F = °C × 9/5 + 32. °C = (°F − 32) × 5/9. K = °C + 273.15.
Example Calculation
Converting 37°C (average human body temperature) to Fahrenheit: (37 × 9/5) + 32 = 66.6 + 32 = 98.6°F. The same 37°C converts to Kelvin with addition only: 37 + 273.15 = 310.15 K. Going the other direction, 0°F converts to Celsius as (0 − 32) × 5/9 = −17.78°C, which then converts to Kelvin as −17.78 + 273.15 ≈ 255.37 K.
Frequently Asked Questions
What is absolute zero?+
Absolute zero is 0 Kelvin, or -273.15°C, the theoretical lowest possible temperature — the calculator will flag any conversion that falls below this.
Why does Fahrenheit use 32 and 9/5?+
The Fahrenheit scale sets water's freezing point at 32°F and boiling point at 212°F (a 180-degree span), compared to Celsius's 0–100 range, producing the 9/5 ratio and 32-degree offset.
Where is Kelvin commonly used?+
Kelvin is the standard unit in scientific contexts, particularly physics and chemistry, since it has no negative values.
Is there a temperature where Celsius and Fahrenheit read the same number?+
Yes — at −40°, both scales agree: −40°C equals −40°F. It's the only point where the two scales intersect, and it falls straight out of solving the conversion formula for the point where °F equals °C.
Why does converting Kelvin to Celsius only require addition, but Celsius to Fahrenheit needs both multiplication and addition?+
Kelvin and Celsius use identically sized degrees — Kelvin is just Celsius shifted so 0 K sits at absolute zero (−273.15°C) — so only the offset changes. Fahrenheit degrees are 5/9 the size of Celsius degrees, so converting between them requires rescaling (the 9/5 factor) in addition to the 32-degree offset.
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<a href="https://everyfix.net/tools/temperature-converter/">Temperature Converter</a> by <a href="https://everyfix.net">EveryFix</a>Related Tools
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