Isaac Newton is famous for gravity and calculus, but he also invented a temperature scale — briefly, around 1700, before thermometers were even standardized. The Newton scale splits the freeze-to-boil range of water into just 33 degrees: 0°N is melting ice and 33°N is boiling water, so each Newton degree is a chunky three Celsius degrees. The conversion is Celsius × 33/100. Type 20 into the Celsius (°C) box and the Newton (°N) readout shows 6.6; a hot 37°C fever reads about 12.2°N. Newton calibrated his scale with a linseed-oil thermometer and reference points like melting snow and boiling water, publishing it in 1701 — then the scale quietly died out as Fahrenheit and Celsius took over. Nobody uses it in a lab today, but it delights physics teachers and trivia lovers, and the bonus Fahrenheit (°F) box keeps the numbers grounded. Converting to Newton degrees is mostly a historical joyride, proof that even geniuses ship version 1.0 ideas that do not catch on.

With the pre-filled defaults — Celsius (°C) 100 — the Celsius to Newton returns Newton (°N) 33.0000, Fahrenheit (°F) 212.0000. Change any input and those results update instantly, so you can see exactly how each number you enter moves the answer.