Temperature · Unit Converter

Convert Megakelvin to Millikelvin

Convert megakelvins to millikelvins instantly. 1 MK = 1e+9 mK — use the live calculator, the exact formula, a reference-temperature table and worked examples. Also check the Millikelvin to Megakelvin 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

SI Prefixed Kelvin

Megakelvin

What is a megakelvin?

One megakelvin (MK) is one million kelvins (10⁶ K).

Origin of the megakelvin

Formed with the SI prefix 'mega-' (from Greek 'megas', great) applied to the kelvin base unit.

Where it is used

Astrophysics and fusion science — the Sun's core burns at about 15.7 MK, and the solar corona runs at 1–3 MK.

When and where it was developed

The mega- prefix dates to the 1873 British Association system and entered the SI in 1960.

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.

Megakelvin to Millikelvin conversion formula

The exact relationship between megakelvins and millikelvins:

mK = MK × 1e+9
MK = mK × 1e-9

To convert megakelvins to millikelvins, multiply the value in megakelvins by 1e+9. To reverse, multiply the value in millikelvins by 1e-9.

Both units count upward from absolute zero, so 0 MK = 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 Megakelvin converter for the reverse direction.

Step-by-step: convert megakelvins to millikelvins

  1. Write down the temperature in megakelvins (MK).
  2. Multiply the value in megakelvins by 1e+9.
  3. The result is the same temperature expressed in millikelvins (mK).
  4. To reverse, multiply the value in millikelvins by 1e-9 — or open the Millikelvin to Megakelvin converter.

Worked examples

Example 1 — Convert 1 MK to mK:
1 × 1e+9 = 1e+9 mK

Example 2 — Convert 100 MK to mK:
100 × 1e+9 = 1e+11 mK

Megakelvin to Millikelvin conversion table

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

Megakelvin [MK]Millikelvin [mK]Reference point
00Absolute zero
0.00023315233150Where Celsius and Fahrenheit coincide (−40°)
0.0002553722255372.2222222222Zero Fahrenheit (0 °F)
0.00027315273150Water freezes (0 °C / 32 °F)
0.00027316273160Triple point of water
0.00028315283150Cool day (10 °C / 50 °F)
0.00029315293150Room temperature (20 °C / 68 °F)
0.00029815298150Standard laboratory temperature (25 °C)
0.00030315303150Hot day (30 °C / 86 °F)
0.00031015310150Human body temperature (37 °C / 98.6 °F)
0.00031315313150Heat-wave day (40 °C / 104 °F)
0.00032315323150Hot tap water (50 °C / 122 °F)
0.00037315373150Water boils (100 °C / 212 °F)
0.00045315453150Moderate baking oven (180 °C / 356 °F)
0.0057785778000Surface of the Sun (≈5,505 °C)

Frequently asked questions

How many millikelvins is 1 megakelvin?
1 megakelvin equals 1e+9 millikelvins.
How do I convert megakelvins to millikelvins?
Use the formula mK = MK × 1e+9: multiply the value in megakelvins by 1e+9.
How do I convert millikelvins back to megakelvins?
Apply the reverse formula MK = mK × 1e-9 — multiply the value in millikelvins by 1e-9 — or use the Millikelvin to Megakelvin converter.
How many millikelvins is 100 megakelvins?
100 megakelvins equals 1e+11 millikelvins, because 100 × 1e+9 = 1e+11.
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 Megakelvin to other temperature units

Show all Megakelvin conversions

Sources & references

Conversion relationship (1 MK = 1e+9 mK) verified against the following authoritative sources:

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