kPa to mmHg Conversion Calculator — Kilopascals to Millimetres of Mercury
Convert kilopascals (kPa) to millimetres of mercury (mmHg) for blood pressure readings, vacuum levels, and clinical measurements. 1 kPa = 7.5006 mmHg. Standard atmospheric pressure is 101.325 kPa = 760 mmHg.
kPa
1 kPa = 1000 Pa / 133.322 Pa per mmHg ≈ 7.5006 mmHg
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Convert kPa to Pascals
13.332 × 1,000 = 13,332 - 2
Divide by Pa per mmHg
13,332 ÷ 133.322 = 99.99821 conventional mmHg = 133.322387 Pa (mercury at 0 °C, standard gravity).
How does this calculator work?
1 kPa = 7.5006 mmHg ≈ 7.5006 Torr = 0.009869 atm = 0.01 bar = 0.14504 psi. Key reference: 101.325 kPa = 760 mmHg = 1 atm. Multiply kPa by 7.5006 to get mmHg; divide mmHg by 7.5006 to get kPa. Common in blood pressure (120 mmHg ≈ 16 kPa) and vacuum engineering.
Formula
How this is calculated
The millimetre of mercury (mmHg) is a legacy pressure unit defined by the height of a mercury column it supports. One conventional mmHg equals 133.322387 Pa — the pressure exerted by exactly 1 mm of mercury at 0 °C under standard gravity (9.80665 m/s²). To convert kPa to mmHg, multiply by 1000 to get Pa, then divide by 133.322387, giving a factor of approximately 7.5006 mmHg per kPa.
The Torr is a closely related unit: 1 atm ≡ 760 Torr exactly, so 1 Torr = 101,325/760 ≈ 133.3224 Pa. This is virtually identical to 1 mmHg (133.3224 Pa vs 133.322387 Pa — a difference of less than 0.0002%), so mmHg and Torr are interchangeable for all practical purposes. Many vacuum gauges display Torr while clinical instruments display mmHg.
In medical contexts, blood pressure is universally reported in mmHg. Normal systolic pressure is about 120 mmHg ≈ 16.0 kPa; normal diastolic is about 80 mmHg ≈ 10.7 kPa. Mercury sphygmomanometers have been largely phased out due to mercury toxicity concerns, but the mmHg unit persists by international convention in clinical practice.
Frequently asked questions
100 kPa = 100,000 Pa / 133.322387 Pa per mmHg ≈ 750.06 mmHg. Standard atmosphere (101.325 kPa) equals exactly 760 mmHg by definition.
1 Torr = 101,325/760 ≈ 133.3224 Pa. 1 mmHg = 133.322387 Pa (mercury at 0 °C, standard gravity). The difference is about 0.0002% — negligible for any measurement. Torr is more precisely defined; mmHg is the clinical standard.
The mercury sphygmomanometer (invented ~1880s) directly displayed mercury column height in millimetres. The unit stuck even as mercury instruments were replaced by digital ones. It is still the legal reporting unit in most countries for blood pressure, and clinical reference ranges worldwide are defined in mmHg.
Also known as
TG we-Calculate Editorial Team. (2026). kPa to mmHg Conversion Calculator — Kilopascals to Millimetres of Mercury [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/kpa-to-mmhg-conversion-calculator
TG we-Calculate Editorial Team. "kPa to mmHg Conversion Calculator — Kilopascals to Millimetres of Mercury." TG we-Calculate. 2026. https://we-calculate.com/calculator/kpa-to-mmhg-conversion-calculator.
TG we-Calculate Editorial Team, "kPa to mmHg Conversion Calculator — Kilopascals to Millimetres of Mercury," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/kpa-to-mmhg-conversion-calculator
@misc{wecalculate_kpa_to_mmhg_conversion_calculator, title = {kPa to mmHg Conversion Calculator — Kilopascals to Millimetres of Mercury}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/kpa-to-mmhg-conversion-calculator}}, year = {2026}, note = {TG we-Calculate} }
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