The Newton scale is a historic temperature scale devised by Isaac Newton around 1700, predating the Celsius scale. It is mostly of historical and educational interest today. This converter translates between Celsius (°C) and degrees Newton (°N) in both directions, instantly and entirely in your browser.
How it works
Newton fixed 0 °N at the freezing point of water and 33 °N at its boiling point, where Celsius uses 0 and 100 for the same two points. Because the Newton scale spans 33 degrees over the same range that Celsius spans 100, each Newton degree is larger and the conversion is a simple factor:
°N = °C × 33 ÷ 100 (that is, °C × 0.33)
To reverse it, multiply by 100 and divide by 33: °C = °N × 100 ÷ 33. There is no offset because both scales share the same zero at water’s freezing point.
Example
Convert 37 °C to the Newton scale:
37 × 0.33 = 12.21 °N
| Celsius (°C) | Newton (°N) |
|---|---|
| 0 °C | 0 °N |
| 20 °C | 6.6 °N |
| 37 °C | 12.21 °N |
| 100 °C | 33 °N |
All conversion happens in your browser — nothing is sent to a server.
Isaac Newton and the origin of this scale
Newton published his temperature observations around 1700, assigning 0 degrees to the freezing point of water and 33 degrees to the boiling point — a deliberate choice, since 33 is approximately 100 divided by 3, giving the scale a rational relationship to body temperature, which he placed at about 12 °N. Newton was an astronomer and mathematician, and his interest in temperature was partly instrumental: he was trying to establish a calibrated scale for studying heat in metals and flames.
The Newton scale never gained wide adoption, superseded first by the Fahrenheit scale and later by Celsius. Today it appears in the history of science, reference tables of historical temperature scales, and occasional trivia about just how many temperature scales have been proposed over the centuries — at least fifteen have names.
Historical context: Newton versus its contemporaries
When Newton devised his scale, Fahrenheit’s and Celsius’s scales did not yet exist. Several competing scales were proposed around the same era:
| Scale | Invented | Freezing point | Boiling point |
|---|---|---|---|
| Newton | ~1700 | 0 °N | 33 °N |
| Fahrenheit | 1724 | 32 °F | 212 °F |
| Réaumur | 1730 | 0 °Ré | 80 °Ré |
| Celsius | 1742 (inverted 1745) | 0 °C | 100 °C |
| Kelvin (absolute) | 1848 | −273.15 °C | — |
The Newton scale’s 33-degree range for water makes each Newton degree about three times larger than a Celsius degree (precisely 100/33 ≈ 3.03 °C per °N). This is slightly different from the Réaumur scale (80 degrees over the same range, so each Réaumur degree ≈ 1.25 °C), showing how arbitrary the choice of boiling-to-freezing span was for each inventor.
When you might use this converter
Practically speaking, this converter is used by:
- History of science students reading Newton’s original papers and needing to contextualise his temperature measurements.
- Physics teachers demonstrating unit analysis and the variety of historical scales.
- Puzzle and trivia enthusiasts who need to verify a Newton-scale value.
- Software developers building tools that must handle all named temperature scales from a reference table.