Skip to content
UnitCalculators.com

Millimetres of mercury to kilopascals

Multiply millimetres of mercury by 0.133322 to get kilopascals.

1 mmHg = 0.133322 kPaNIST SP 811
mmHg
15.9987kPa

120 mmHg = 15.9987 kPa

How to convert millimetres of mercury to kilopascals

The kilopascal is one thousand pascals (10³ Pa), the metric pressure unit. The millimetre of mercury is the conventional millimetre of mercury, exactly 101325/760 pascals (about 133.322 Pa), equal to the torr.

Worked example — 120 mmHg: 120 × 0.133322 = 15.9987 kPa.

Millimetres of mercury to kilopascals table

Common conversions. The reverse table is on kilopascals to millimetres of mercury.
Millimetres of mercuryKilopascals
60 mmHg7.9993 kPa
80 mmHg10.6658 kPa
90 mmHg11.999 kPa
100 mmHg13.3322 kPa
120 mmHg15.9987 kPa
140 mmHg18.6651 kPa
160 mmHg21.3316 kPa
200 mmHg26.6645 kPa
760 mmHg101.325 kPa

Reverse and related

About millimetres of mercury and kilopascals

Millimetre of mercury (mmHg)

1 mmHg = 0.133322 kPa

Definition. The conventional millimetre of mercury, exactly 101325/760 pascals (about 133.322 Pa), equal to the torr

History and origin

The millimetre of mercury comes from mercury barometers, where pressure was read as the height of a mercury column. It is now fixed conventionally as one 760th of a standard atmosphere, essentially equal to the torr.

Current use

mmHg is the standard unit for blood pressure — a reading of 120/80 mmHg — and for measuring vacuums.

Source: NIST SP 811, App. B; ISO 80000-4. Exact SI values are definitional (bar = 10⁵ Pa, atm = 101 325 Pa) or derived from the pound (NIST HB 44) and standard gravity 9.80665 m/s² (psi)

Kilopascal (kPa)

1 kPa = 7.5006 mmHg

Definition. One thousand pascals (10³ Pa), the metric pressure unit

History and origin

The kilopascal is one thousand pascals, a metric multiple of the SI pressure unit. It gives conveniently sized numbers for everyday pressures.

Current use

Kilopascals are used for tyre pressure in metric countries and throughout engineering.

Source: NIST SP 811, App. B; ISO 80000-4. Exact SI values are definitional (bar = 10⁵ Pa, atm = 101 325 Pa) or derived from the pound (NIST HB 44) and standard gravity 9.80665 m/s² (psi)

Where people use this

Millimetres of mercury: blood pressure, vacuum measurement. Kilopascals: tyre pressure (metric), engineering. A 120 mmHg blood-pressure reading is about 16 kPa.

How we know this is right
The factor is fixed by the standards that define the units, not chosen — so it is exact, not a measurement:
1 kPa = 7.500616827 mmHg, so 1 mmHg = 1 ÷ 7.500616827 = 0.133322 kPa.

Every value is carried to full double precision; the display is rounded.

Both units are defined in NIST SP 811, App. B; ISO 80000-4. Exact SI values are definitional (bar = 10⁵ Pa, atm = 101 325 Pa) or derived from the pound (NIST HB 44) and standard gravity 9.80665 m/s² (psi).

Questions people ask

How many kPa is 120 mmHg?

A 120 mmHg reading is about 16 kPa. To convert mmHg to kPa, multiply by 0.1333.

How many kPa in a mmHg?

One mmHg is about 0.133 kPa.

What is 120/80 mmHg in kPa?

A 120/80 mmHg blood pressure is about 16/10.7 kPa.

How many kPa is 760 mmHg?

760 mmHg, which is one atmosphere, is about 101.3 kPa.

All millimetre of mercury conversions