View source for Conversion of scales of temperature

{{short description|Comparison of various temperature scales}}
This is a collection of [[Physics:Temperature|temperature]] '''conversion''' formulas and comparisons among eight different temperature scales, several of which have long been obsolete.

Temperatures on scales that either do not share a numeric zero or are nonlinearly related cannot correctly be mathematically equated (related using the symbol =), and thus temperatures on different scales are more correctly described as corresponding (related using the symbol ≘).

== Celsius scale ==
{{Details|Celsius}}
{{temperature|C}}

== Kelvin scale ==
{{Details|Kelvin}}
{{temperature|K}}

== Fahrenheit scale ==
{{Details|Fahrenheit}}
{{temperature|F}}

== Rankine scale ==
{{Details|Rankine scale}}
{{temperature|R}}

== Delisle scale ==
{{Details|Delisle scale}}
{{temperature|De}}

== Newton scale ==
{{Details|Newton scale}}
{{temperature|N}}

== Réaumur scale ==
{{Details|Réaumur scale}}
{{temperature|Re}}

== Rømer scale ==
{{Details|Rømer scale}}
{{temperature|Ro}}

==Comparison values chart==
{| class="wikitable" style="text-align:center"
|-
! Celsius !! Fahrenheit !! Kelvin !! Rankine !! Delisle !! Newton !! Réaumur !! Rømer
|-
| 500.00 || 932.00 || 773.15 || 1391.67 || −600.00 || 165.00 || 400.00 || 270.00
|-
| 490.00 || 914.00 || 763.15 || 1373.67 || −585.00 || 161.70 || 392.00 || 264.75
|-
| 480.00 || 896.00 || 753.15 || 1355.67 || −570.00 || 158.40 || 384.00 || 259.50
|-
| 470.00 || 878.00 || 743.15 || 1337.67 || −555.00 || 155.10 || 376.00 || 254.25
|-
| 460.00 || 860.00 || 733.15 || 1319.67 || −540.00 || 151.80 || 368.00 || 249.00
|-
| 450.00 || 842.00 || 723.15 || 1301.67 || −525.00 || 148.50 || 360.00 || 243.75
|-
| 440.00 || 824.00 || 713.15 || 1283.67 || −510.00 || 145.20 || 352.00 || 238.50
|-
| 430.00 || 806.00 || 703.15 || 1265.67 || −495.00 || 141.90 || 344.00 || 233.25
|-
| 420.00 || 788.00 || 693.15 || 1247.67 || −480.00 || 138.60 || 336.00 || 228.00
|-
| 410.00 || 770.00 || 683.15 || 1229.67 || −465.00 || 135.30 || 328.00 || 222.75
|-
| 400.00 || 752.00 || 673.15 || 1211.67 || −450.00 || 132.00 || 320.00 || 217.50
|-
| 390.00 || 734.00 || 663.15 || 1193.67 || −435.00 || 128.70 || 312.00 || 212.25
|-
| 380.00 || 716.00 || 653.15 || 1175.67 || −420.00 || 125.40 || 304.00 || 207.00
|-
| 370.00 || 698.00 || 643.15 || 1157.67 || −405.00 || 122.10 || 296.00 || 201.75
|-
| 360.00 || 680.00 || 633.15 || 1139.67 || −390.00 || 118.80 || 288.00 || 196.50
|-
| 350.00 || 662.00 || 623.15 || 1121.67 || −375.00 || 115.50 || 280.00 || 191.25
|-
| 340.00 || 644.00 || 613.15 || 1103.67 || −360.00 || 112.20 || 272.00 || 186.00
|-
| 330.00 || 626.00 || 603.15 || 1085.67 || −345.00 || 108.90 || 264.00 || 180.75
|-
| 320.00 || 608.00 || 593.15 || 1067.67 || −330.00 || 105.60 || 256.00 || 175.50
|-
| 310.00 || 590.00 || 583.15 || 1049.67 || −315.00 || 102.30 || 248.00 || 170.25
|-
| 300.00 || 572.00 || 573.15 || 1031.67 || −300.00 || 99.00 || 240.00 || 165.00
|-
| 290.00 || 554.00 || 563.15 || 1013.67 || −285.00 || 95.70 || 232.00 || 159.75
|-
| 280.00 || 536.00 || 553.15 || 995.67 || −270.00 || 92.40 || 224.00 || 154.50
|-
| 270.00 || 518.00 || 543.15 || 977.67 || −255.00 || 89.10 || 216.00 || 149.25
|-
| 260.00 || 500.00 || 533.15 || 959.67 || −240.00 || 85.80 || 208.00 || 144.00
|-
| 250.00 || 482.00 || 523.15 || 941.67 || −225.00 || 82.50 || 200.00 || 138.75
|-
| 240.00 || 464.00 || 513.15 || 923.67 || −210.00 || 79.20 || 192.00 || 133.50
|-
| 230.00 || 446.00 || 503.15 || 905.67 || −195.00 || 75.90 || 184.00 || 128.25
|-
| 220.00 || 428.00 || 493.15 || 887.67 || −180.00 || 72.60 || 176.00 || 123.00
|-
| 210.00 || 410.00 || 483.15 || 869.67 || −165.00 || 69.30 || 168.00 || 117.75
|-
| 200.00 || 392.00 || 473.15 || 851.67 || −150.00 || 66.00 || 160.00 || 112.50
|-
| 190.00 || 374.00 || 463.15 || 833.67 || −135.00 || 62.70 || 152.00 || 107.25
|-
| 180.00 || 356.00 || 453.15 || 815.67 || −120.00 || 59.40 || 144.00 || 102.00
|-
| 170.00 || 338.00 || 443.15 || 797.67 || −105.00 || 56.10 || 136.00 || 96.75
|-
| 160.00 || 320.00 || 433.15 || 779.67 || −90.00 || 52.80 || 128.00 || 91.50
|-
| 150.00 || 302.00 || 423.15 || 761.67 || −75.00 || 49.50 || 120.00 || 86.25
|-
| 140.00 || 284.00 || 413.15 || 743.67 || −60.00 || 46.20 || 112.00 || 81.00
|-
| 130.00 || 266.00 || 403.15 || 725.67 || −45.00 || 42.90 || 104.00 || 75.75
|-
| 120.00 || 248.00 || 393.15 || 707.67 || −30.00 || 39.60 || 96.00 || 70.50
|-
| 110.00 || 230.00 || 383.15 || 689.67 || −15.00 || 36.30 || 88.00 || 65.25
|-
| 100.00 || 212.00 || 373.15 || 671.67 || '''0.00''' || 33.00 || 80.00 || 60.00
|-
| 90.00 || 194.00 || 363.15 || 653.67 || 15.00 || 29.70 || 72.00 || 54.75
|-
| 80.00 || 176.00 || 353.15 || 635.67 || 30.00 || 26.40 || 64.00 || 49.50
|-
| 70.00 || 158.00 || 343.15 || 617.67 || 45.00 || 23.10 || 56.00 || 44.25
|-
| 60.00 || 140.00 || 333.15 || 599.67 || 60.00 || 19.80 || 48.00 || 39.00
|-
| 50.00 || 122.00 || 323.15 || 581.67 || 75.00 || 16.50 || 40.00 || 33.75
|-
| 40.00 || 104.00 || 313.15 || 563.67 || 90.00 || 13.20 || 32.00 || 28.50
|-
| 30.00 || 86.00 || 303.15 || 545.67 || 105.00 || 9.90 || 24.00 || 23.25
|-
| 20.00 || 68.00 || 293.15 || 527.67 || 120.00 || 6.60 || 16.00 || 18.00
|-
| 10.00 || 50.00 || 283.15 || 509.67 || 135.00 || 3.30 || 8.00 || 12.75
|-
| '''0.00''' || 32.00 || 273.15 || 491.67 || 150.00 || '''0.00''' || '''0.00''' || 7.50
|-
| −10.00 || 14.00 || 263.15 || 473.67 || 165.00 || −3.30 || −8.00 || 2.25
|-
| -14.26 || 6.29 || 258.86 || 465.96 || 171.43 || -4.71 || -11.43 || '''0.00'''
|-
| -17.78 || '''0.00''' || 255.37 || 459.67 || 176.67 || -5.87 || -14.22 || -1.83
|-
| −20.00 || −4.00 || 253.15 || 455.67 || 180.00 || −6.60 || −16.00 || −3.00
|-
| −30.00 || −22.00 || 243.15 || 437.67 || 195.00 || −9.90 || −24.00 || −8.25
|-
| −40.00 || −40.00 || 233.15 || 419.67 || 210.00 || −13.20 || −32.00 || −13.50
|-
| −50.00 || −58.00 || 223.15 || 401.67 || 225.00 || −16.50 || −40.00 || −18.75
|-
| −60.00 || −76.00 || 213.15 || 383.67 || 240.00 || −19.80 || −48.00 || −24.00
|-
| −70.00 || −94.00 || 203.15 || 365.67 || 255.00 || −23.10 || −56.00 || −29.25
|-
| −80.00 || −112.00 || 193.15 || 347.67 || 270.00 || −26.40 || −64.00 || −34.50
|-
| −90.00 || −130.00 || 183.15 || 329.67 || 285.00 || −29.70 || −72.00 || −39.75
|-
| −100.00 || −148.00 || 173.15 || 311.67 || 300.00 || −33.00 || −80.00 || −45.00
|-
| −110.00 || −166.00 || 163.15 || 293.67 || 315.00 || −36.30 || −88.00 || −50.25
|-
| −120.00 || −184.00 || 153.15 || 275.67 || 330.00 || −39.60 || −96.00 || −55.50
|-
| −130.00 || −202.00 || 143.15 || 257.67 || 345.00 || −42.90 || −104.00 || −60.75
|-
| −140.00 || −220.00 || 133.15 || 239.67 || 360.00 || −46.20 || −112.00 || −66.00
|-
| −150.00 || −238.00 || 123.15 || 221.67 || 375.00 || −49.50 || −120.00 || −71.25
|-
| −160.00 || −256.00 || 113.15 || 203.67 || 390.00 || −52.80 || −128.00 || −76.50
|-
| −170.00 || −274.00 || 103.15 || 185.67 || 405.00 || −56.10 || −136.00 || −81.75
|-
| −180.00 || −292.00 || 93.15 || 167.67 || 420.00 || −59.40 || −144.00 || −87.00
|-
| −190.00 || −310.00 || 83.15 || 149.67 || 435.00 || −62.70 || −152.00 || −92.25
|-
| −200.00 || −328.00 || 73.15 || 131.67 || 450.00 || −66.00 || −160.00 || −97.50
|-
| −210.00 || −346.00 || 63.15 || 113.67 || 465.00 || −69.30 || −168.00 || −102.75
|-
| −220.00 || −364.00 || 53.15 || 95.67 || 480.00 || −72.60 || −176.00 || −108.00
|-
| −230.00 || −382.00 || 43.15 || 77.67 || 495.00 || −75.90 || −184.00 || −113.25
|-
| −240.00 || −400.00 || 33.15 || 59.67 || 510.00 || −79.20 || −192.00 || −118.50
|-
| −250.00 || −418.00 || 23.15 || 41.67 || 525.00 || −82.50 || −200.00 || −123.75
|-
| −260.00 || −436.00 || 13.15 || 23.67 || 540.00 || −85.80 || −208.00 || −129.00
|-
| −270.00 || −454.00 || 3.15 || 5.67 || 555.00 || −89.10 || −216.00 || −134.25
|-
| −273.15 || −459.67 || '''0.00''' || '''0.00''' || 559.725 || −90.1395 || −218.52 || −135.90375
|-
! Celsius !! Fahrenheit !! Kelvin !! Rankine !! Delisle !! Newton !! Réaumur !! Rømer
|-
|}

==Comparison of temperature scales{{anchor|Comparison}}==
{| class="wikitable" style="text-align:right;"
|+ '''Comparison of temperature scales'''
|-
! Comment
! [[Kelvin]]
! [[Celsius]]
! [[Fahrenheit]]
! [[Physics:Rankine scale|Rankine]]
! [[Delisle scale|Delisle]]
! [[Newton scale|Newton]]
! [[Réaumur scale|Réaumur]]
! [[Rømer scale|Rømer]]
|-
| style="text-align:left;" | [[Physics:Absolute zero|Absolute zero]]
|  0.00
| −273.15
| −459.67
|  0.00
|  559.73
| −90.14
| −218.52
| −135.90
|-
| style="text-align:left;" | [[Earth:Lowest temperature recorded on Earth|Lowest recorded surface temperature on Earth]]<ref name="VS">[https://www.expertsure.com/2008/12/14/the-coldest-inhabited-places-on-earth/ The Coldest Inhabited Places on Earth]; researchers of the Vostok Station recorded the coldest known temperature on Earth on July 21st 1983: −89.2&nbsp;°C (−128.6&nbsp;°F).</ref>
|  184
| −89.2<ref name="VS" />
| −128.6<ref name="VS" />
|  331
|  284
| −29
| −71
| −39
|-
| style="text-align:left;" | Fahrenheit's ice/salt mixture
|  255.37
| −17.78
|  0.00
|  459.67
|  176.67
| −5.87
| −14.22
| −1.83
|-
| style="text-align:left;" | Ice melts (at [[Standard conditions for temperature and pressure|standard pressure]])
| 273.15
| 0.00
| 32.00
| 491.67
| 150.00
| 0.00
| 0.00
| 7.50
|-
| style="text-align:left;" | [[Chemistry:Triple point|Triple point]] of water
| 273.16
| 0.01
| 32.018
| 491.688
| 149.985
| 0.0033
| 0.008
| 7.50525
|-
| style="text-align:left;" | Average surface temperature on Earth
| 288
| 15
| 59
| 519
| 128
| 5
| 12
| 15
|-
| style="text-align:left;" | Average [[Physics:Human body temperature|human body temperature]]*
| 310
| 37
| 98
| 558
| 95
| 12
| 29
| 27
|-
| style="text-align:left;" | [[Physics:Highest temperature recorded on Earth|Highest recorded surface temperature on Earth]]<ref name="ASU">{{cite web |url=http://wmo.asu.edu/world-highest-temperature |title=World: Highest Temperature | date=November 12, 2007| website= Arizona State University, School of Geographical Sciences |archiveurl=https://web.archive.org/web/20130104143844/http://wmo.asu.edu/world-highest-temperature |archivedate=January 4, 2013 |quote= an Italian weather station in al 'Aziziyah ([[Place:Libya|Libya]]) measured a temperature of 58&nbsp;°C (136.4&nbsp;°F) on September 13th 1922. ''"Although this record has gained general acceptance as the world's highest temperature recorded under standard conditions, the validity of the extreme has been questioned."''}}</ref>
| 331
| 58<ref name="ASU" />
| 136.4<ref name="ASU" />
| 596
| 63
| 19
| 46
| 38
|-
| style="text-align:left;" | Water boils (at [[Standard temperature and pressure|standard pressure]])
| 373.1339
| 99.9839
| 211.97102
| 671.64102
| 0.00
| 33.00
| 80.00
| 60.00
|-
| style="text-align:left;" | [[Chemistry:Titanium|Titanium]] melts
| 1941
| 1668
| 3034
| 3494
| −2352
| 550
| 1334
| 883
|-
| style="text-align:left;" | The [[Astronomy:Photosphere|surface of the Sun]]
|  5800
|  5500
|  9900
|  10400
| −8100
|  1800
|  4400
|  2900
|}

{{refbegin}}
<nowiki>*</nowiki> Normal human body temperature is 36.8&nbsp;°C ±0.7&nbsp;°C, or 98.2&nbsp;°F ±1.3&nbsp;°F.  The commonly given value 98.6&nbsp;°F is simply the exact conversion of the nineteenth-century German standard of 37&nbsp;°C. Since it does not list an acceptable range, it could therefore be said to have excess (invalid) precision.<ref>{{cite web
| url=https://hypertextbook.com/facts/1997/LenaWong.shtml
| title=Temperature of a healthy human (body temperature)
| first=Lena
| last=Wong
| year=1997
| website=The Physics Factbook
| editor-last=Elert
| editor-first=Glenn
| accessdate=2018-06-07}}</ref>

Some numbers in this table have been rounded.
{{refend}}
{{anchor|scales_xy}}

=== Graphical representation ===
<div style="overflow:auto">
{| width="10px" cellpadding="0" cellspacing="0"
|-
| colspan="10" rowspan="5" style="vertical-align: top;" |
<imagemap>
:File:Comparison of temperature scales blank.svg|845x580px|
circle 40 330 4  [[:File:Comparison of temperature scales blank.svg|0 K / 0 °R (−273.15 °C)]]
circle 504 330 4 [[:File:Comparison of temperature scales blank.svg|0 °F (−17.78 °C)]]
circle 537 270 4 [[:File:Comparison of temperature scales blank.svg|150 °D]]
circle 537 317 4 [[:File:Comparison of temperature scales blank.svg|32 °F]]
circle 537 325 4 [[:File:Comparison of temperature scales blank.svg|7.5 °Rø]]
circle 537 332 4 [[:File:Comparison of temperature scales blank.svg|0 °C / 0 °Ré / 0 °N]]
circle 718 245 4 [[:File:Comparison of temperature scales blank.svg|212 °F]]
circle 718 290 4 [[:File:Comparison of temperature scales blank.svg|100 °C]]
circle 718 298 4 [[:File:Comparison of temperature scales blank.svg|80 °Ré]]
circle 718 306 4 [[:File:Comparison of temperature scales blank.svg|60 °Rø]]
circle 718 317 4 [[:File:Comparison of temperature scales blank.svg|33 °N]]
circle 718 330 4 [[:File:Comparison of temperature scales blank.svg|0 °D]]
rect 0 0 845 580 [[:File:Comparison of temperature scales blank.svg]]
desc none
</imagemap>
| style="vertical-align: top; height: 142px;"                                         | [[Physics:Rankine scale|Rankine]] (°R)
|-
| style="vertical-align: top; height: 42px;"                                          | [[Kelvin]] (K)
|-
| style="vertical-align: top; height: 69px; white-space: nowrap;"                     | [[Fahrenheit]] (°F)
|-
| style="vertical-align: top; height: 106px; line-height: 20.5px; white-space: nowrap;" | [[Celsius]] (°C)<br />[[Réaumur scale|Réaumur]] (°Ré)<br />[[Rømer scale|Rømer]] (°Rø)<br />[[Newton scale|Newton]] (°N)
|-
| style="vertical-align: top; height: 220px;"                                         | [[Delisle scale|Delisle]] (°D)
|- style="vertical-align: top;"
| style="width: 10px;" | &thinsp;
| style="width: 60px;  text-align: center;" | [[Physics:Absolute zero|Absolute zero]]
| style="width: 110px; text-align: center;" | [[Earth:Lowest temperature recorded on Earth|Lowest recorded surface temperature on Earth]]<ref name="VS" />
| style="width: 110px; text-align: center;" | [[Fahrenheit#History|Fahrenheit's ice/water/salt mixture]]
| style="width: 110px; text-align: center;" | [[Physics:Melting point|Melting point]] of ice (at [[Standard conditions for temperature and pressure|standard pressure]])
| style="width: 110px; text-align: center;" | Average surface temperature on Earth (15&nbsp;°C)
| style="width: 110px; text-align: center;" | Average [[Physics:Human body temperature|human body temperature]] (37&nbsp;°C)
| style="width: 110px; text-align: center;" | [[Physics:Highest temperature recorded on Earth|Highest recorded surface temperature on Earth]]<ref name="ASU" />
| style="width: 110px; text-align: center;" | [[Physics:Boiling point|Boiling point]] of water (at standard pressure)
| style="width: 5px;" | &thinsp;
| &nbsp;
|}</div>

==Conversion table between the different temperature units==
{{Timeline Temperature Conversion}}

== Converting units of temperature differences ==
Converting units of temperature differences (also referred to as temperature deltas) is not the same as converting absolute temperature values, and different formulae must be used.

To convert a delta temperature from Fahrenheit to Celsius, the formula is {{nowrap|1={Δ''T''}<sub>°F</sub> = {{sfrac|9|5}}{Δ''T''}<sub>°C</sub>.}}

To convert a delta temperature from Celsius to Kelvin, it is 1:1 {{nowrap|1=({Δ''T''}<sub>°C</sub> = {Δ''T''}<sub>K</sub>).}}

== See also ==
* [[Outline of metrology and measurement]]
* [[Physics:Degree of frost|Degree of frost]]
* [[Conversion of units]]
* [[Physics:Gas mark|Gas mark]]

== Notes and references==
{{Reflist|30em}}

{{Scales of temperature}}

[[Category:Scales of temperature]]
[[Category:Conversion of units of measurement]]

{{Sourceattribution|Conversion of scales of temperature}}