Temperature · Unit Converter

Convert Triple Point of Water to Millikelvin

Convert triple points of water to millikelvins instantly. 1 TPW = 273160 mK — use the live calculator, the exact formula, a reference-temperature table and worked examples. Also check the Millikelvin to Triple Point of Water converter for the reverse conversion.

Written by Sunith Babu L, Ph.D., Lead Engineer Reviewed by Girish V Kulkarni Ph.D.
Temperature category 2 min read Published Last reviewed Updated

Units explained

Scientific & Fixed-Point

Triple Point of Water

What is the 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.

Origin of the triple point of water

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.

Where it is used

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.

When and where it was developed

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.

SI Prefixed Kelvin

Millikelvin

What is a millikelvin?

One millikelvin (mK) is one thousandth of a kelvin (10⁻³ K), measured upward from absolute zero.

Origin of the millikelvin

Formed with the SI prefix 'milli-' (from Latin 'mille', a thousand) applied to the kelvin base unit.

Where it is used

Cryogenics and low-temperature physics — the dilution refrigerators that cool superconducting quantum computers operate at roughly 10–20 mK.

When and where it was developed

The milli- prefix belongs to the original metric system of 1795 and was carried into the SI in 1960; the kelvin became an SI base unit in 1954.

Triple Point of Water to Millikelvin conversion formula

The exact relationship between triple points of water and millikelvins:

mK = TPW × 273160
TPW = mK × 3.660858e-6

To convert triple points of water to millikelvins, multiply the value in triple points of water by 273160. To reverse, multiply the value in millikelvins by 3.660858e-6.

Both units count upward from absolute zero, so 0 TPW = 0 mK and the relationship is a pure ratio.

How to use this converter

Type a value into the calculator. The result in millikelvins updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Millikelvin to Triple Point of Water converter for the reverse direction.

Step-by-step: convert triple points of water to millikelvins

  1. Write down the temperature in triple points of water (TPW).
  2. Multiply the value in triple points of water by 273160.
  3. The result is the same temperature expressed in millikelvins (mK).
  4. To reverse, multiply the value in millikelvins by 3.660858e-6 — or open the Millikelvin to Triple Point of Water converter.

Worked examples

Example 1 — Convert 1 TPW to mK:
1 × 273160 = 273160 mK

Example 2 — Convert 100 TPW to mK:
100 × 273160 = 2.7316e+7 mK

Triple Point of Water to Millikelvin conversion table

Physically meaningful reference temperatures, from absolute zero to the surface of the Sun, converted from triple points of water to millikelvins:

Triple Point of Water [TPW]Millikelvin [mK]Reference point
00Absolute zero
0.8535290672233150Where Celsius and Fahrenheit coincide (−40°)
0.9348814695255372.2222222222Zero Fahrenheit (0 °F)
0.9999633914273150Water freezes (0 °C / 32 °F)
1273160Triple point of water
1.0365719725283150Cool day (10 °C / 50 °F)
1.0731805535293150Room temperature (20 °C / 68 °F)
1.091484844298150Standard laboratory temperature (25 °C)
1.1097891346303150Hot day (30 °C / 86 °F)
1.1354151413310150Human body temperature (37 °C / 98.6 °F)
1.1463977156313150Heat-wave day (40 °C / 104 °F)
1.1830062967323150Hot tap water (50 °C / 122 °F)
1.3660492019373150Water boils (100 °C / 212 °F)
1.6589178503453150Moderate baking oven (180 °C / 356 °F)
21.15243813155778000Surface of the Sun (≈5,505 °C)

Frequently asked questions

How many millikelvins is 1 triple point of water?
1 triple point of water equals 273160 millikelvins.
How do I convert triple points of water to millikelvins?
Use the formula mK = TPW × 273160: multiply the value in triple points of water by 273160.
How do I convert millikelvins back to triple points of water?
Apply the reverse formula TPW = mK × 3.660858e-6 — multiply the value in millikelvins by 3.660858e-6 — or use the Millikelvin to Triple Point of Water converter.
How many millikelvins is 100 triple points of water?
100 triple points of water equals 2.7316e+7 millikelvins, because 100 × 273160 = 2.7316e+7.
Can a temperature be below absolute zero?
No. Absolute zero (0 K = −273.15 °C = −459.67 °F) is the floor of the thermodynamic temperature scale. The calculator flags any input that would fall below it.

Convert Triple Point of Water to other temperature units

Show all Triple Point of Water conversions

Sources & references

Conversion relationship (1 TPW = 273160 mK) verified against the following authoritative sources:

Results are provided for general reference. Verify critical measurements against an authoritative standard.