Convert Triple Point of Water to Fahrenheit
Convert triple points of water to degrees fahrenheit instantly. °F = (TPW × 491.688) − 459.67 — use the live calculator, the exact formula, a reference-temperature table and worked examples. Also check the Fahrenheit to Triple Point of Water converter for the reverse conversion.
Units explained
Triple Point of Water
The triple point of water is the unique state at which ice, liquid water, and water vapor coexist in equilibrium — exactly 273.16 K (0.01 °C). Treated as a converter unit, 1 triple point of water equals exactly 273.16 kelvins.
Adopted as thermometry's master fixed point because it is exactly reproducible in a sealed glass cell, unlike freezing and boiling points, which shift with atmospheric pressure and dissolved impurities.
Calibration laboratories and the International Temperature Scale of 1990 (ITS-90); from 1954 to 2019 the kelvin itself was defined as exactly 1/273.16 of this temperature.
Fixed at exactly 273.16 K by the 10th CGPM in 1954; it remained the kelvin's defining point until the 2019 SI redefinition through the Boltzmann constant.
Fahrenheit
The degree Fahrenheit (°F) sets the freezing point of water at 32 °F and the boiling point at 212 °F, dividing the interval into 180 equal degrees. One degree Fahrenheit is exactly 5/9 the size of a kelvin, and °F = °C × 9/5 + 32 exactly.
Created by German-born physicist Daniel Gabriel Fahrenheit, inventor of the reliable mercury-in-glass thermometer. His zero point was the temperature of an ice-and-salt brine mixture, and his original upper fixed point sat near human body temperature.
The official everyday scale of the United States and a handful of other countries. In India, clinical thermometers and fever readings are still very commonly quoted in Fahrenheit (a '102-degree fever'), which keeps °F to °C conversion a daily need.
Introduced by Daniel Gabriel Fahrenheit in 1724 in Amsterdam, building directly on Ole Rømer's earlier scale, which Fahrenheit had studied during a 1708 visit to Copenhagen.
Triple Point of Water to Fahrenheit conversion formula
The exact relationship between triple points of water and degrees fahrenheit:
To convert triple points of water to degrees fahrenheit, multiply the value by 491.688, then subtract 459.67. To reverse, add 459.67 to the value, then multiply by 0.002033810058.
Reference anchors: water freezes at 0.9999633914 TPW = 32 °F and boils at 1.3660492019 TPW = 212 °F (at standard atmospheric pressure).
How to use this converter
Type a value into the calculator. The result in degrees fahrenheit updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Fahrenheit to Triple Point of Water converter for the reverse direction.
Step-by-step: convert triple points of water to degrees fahrenheit
- Write down the temperature in triple points of water (TPW).
- Multiply the value by 491.688, then subtract 459.67.
- The result is the same temperature expressed in degrees fahrenheit (°F).
- To reverse, add 459.67 to the value, then multiply by 0.002033810058 — or open the Fahrenheit to Triple Point of Water converter.
Worked examples
Example 1 — Convert 1 TPW to °F:
(1 × 491.688) − 459.67 = 32.018 °F
Example 2 — Convert 100 TPW to °F:
(100 × 491.688) − 459.67 = 48709.13 °F
Triple Point of Water to Fahrenheit conversion table
Physically meaningful reference temperatures, from absolute zero to the surface of the Sun, converted from triple points of water to degrees fahrenheit:
| Triple Point of Water [TPW] | Fahrenheit [°F] | Reference point |
|---|---|---|
| 0 | -459.67 | Absolute zero |
| 0.8535290672 | -40 | Where Celsius and Fahrenheit coincide (−40°) |
| 0.9348814695 | 0 | Zero Fahrenheit (0 °F) |
| 0.9999633914 | 32 | Water freezes (0 °C / 32 °F) |
| 1 | 32.018 | Triple point of water |
| 1.0365719725 | 50 | Cool day (10 °C / 50 °F) |
| 1.0731805535 | 68 | Room temperature (20 °C / 68 °F) |
| 1.091484844 | 77 | Standard laboratory temperature (25 °C) |
| 1.1097891346 | 86 | Hot day (30 °C / 86 °F) |
| 1.1354151413 | 98.6 | Human body temperature (37 °C / 98.6 °F) |
| 1.1463977156 | 104 | Heat-wave day (40 °C / 104 °F) |
| 1.1830062967 | 122 | Hot tap water (50 °C / 122 °F) |
| 1.3660492019 | 212 | Water boils (100 °C / 212 °F) |
| 1.6589178503 | 356 | Moderate baking oven (180 °C / 356 °F) |
| 21.1524381315 | 9940.73 | Surface of the Sun (≈5,505 °C) |
Frequently asked questions
What is 1 TPW in °F?
How do I convert triple points of water to degrees fahrenheit?
How do I convert degrees fahrenheit back to triple points of water?
At what temperature do the Triple Point of Water and Fahrenheit scales read the same number?
Can a temperature be below absolute zero?
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Modern Standard Scales (4 units)
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Scientific & Fixed-Point (2 units)
Sources & references
Conversion relationship (°F = (TPW × 491.688) − 459.67) verified against the following authoritative sources:
- BIPM — The International System of Units (SI Brochure 9th ed.)
Official BIPM publication defining the seven SI base units (including the meter) and the rules for their use. The global authority on units of measurement.
- NIST — Guide to the SI
US National Institute of Standards and Technology reference covering the SI base and derived units with definitions and usage rules for US technical practice.
- NIST Special Publication 811 — Guide for the Use of the International System of Units
Detailed NIST guide covering exact conversion factors between SI and US customary units along with formatting and rounding conventions.
- BIPM — International Temperature Scale of 1990 (ITS-90)
The internationally agreed practical temperature scale, defining fixed points (including the triple point of water at 273.16 K) and interpolation instruments used by national metrology institutes for thermometer calibration worldwide.
- CODATA Internationally Recommended Values of the Fundamental Physical Constants
Committee on Data of the International Science Council; authoritative source for the masses of fundamental particles (electron, proton, neutron) and the atomic mass constant.