Temperature
converter
Type in any scale, Celsius, Fahrenheit or kelvin, and the other two update live. With the reference points that make foreign forecasts and oven dials make sense.
Prefer a physical calculator?
A few solid picks. As an Amazon Associate, Calculate.to earns from qualifying purchases, at no extra cost to you.
OSALO Desktop Calculator
Extra-large 12-digit LCD, giant buttons, solar + battery, the classic office desk workhorse.
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Helix Oxford Scientific
240-function scientific calculator for KS3–KS4 maths, with hard cover. Exam-friendly, plastic-free packaging.
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Casio fx-83GTCW+
The UK classroom-standard scientific calculator (also in pink), allowed in most UK exams.
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ROATEE Construction Calc
Feet-inch-fraction engineering calculator for carpenters, framers and contractors on site.
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Three scales, two formulas
Celsius pins 0 and 100 to water freezing and boiling. Fahrenheit runs the same span from 32 to 212, hence the 9/5 slope. Kelvin is Celsius shifted to start at absolute zero (−273.15°C), which is why science uses it: no negative temperatures exist.
Anchor points worth memorizing
37°C = 98.6°F body · 100°C = 212°F boiling · 180°C = 356°F oven
Quick mental version: double the Celsius and add 30, close enough for weather (20°C → ~70°F). For kitchen work in cups and grams instead, the cups-to-grams converter handles the other half of recipe translation.
Temperature FAQ
Multiply by 9/5 and add 32: 20°C × 1.8 + 32 = 68°F. For quick mental weather math, double it and add 30.
−40 degrees, the two lines cross there. It's the only point where Celsius and Fahrenheit agree.
Science, it starts at absolute zero (−273.15°C), the coldest possible temperature, so no values are negative. A kelvin step equals a Celsius step; only the zero point differs.
About 37°C or 98.6°F, with normal individual variation of half a degree Celsius either way.