Kilopascals to mmHg
Convert kilopascals (kPa) to mmhg (mmHg). Both measure force per area, and the conversion comes up in weather, automotive, diving work.
The Formula
``
mmhg = kilopascals × 7.50061575846
kilopascals = mmhg × 0.133322387415
`
One kilopascal is 7.5006 mmhg, and one mmhg is 0.133322 kilopascals.
Conversion Table
| Kilopascals | mmHg |
|---|---|
| 1 kPa | 7.5006 mmHg |
| 2 kPa | 15.0012 mmHg |
| 5 kPa | 37.5031 mmHg |
| 10 kPa | 75.0062 mmHg |
| 25 kPa | 187.5154 mmHg |
| 50 kPa | 375.0308 mmHg |
| 100 kPa | 750.0616 mmHg |
| 500 kPa | 3,750.31 mmHg |
| 1,000 kPa | 7,500.62 mmHg |
The Other Direction
| mmHg | Kilopascals |
|---|---|
| 1 mmHg | 0.133322 kPa |
| 2 mmHg | 0.266645 kPa |
| 5 mmHg | 0.666612 kPa |
| 10 mmHg | 1.3332 kPa |
| 25 mmHg | 3.3331 kPa |
| 50 mmHg | 6.6661 kPa |
| 100 mmHg | 13.3322 kPa |
| 500 mmHg | 66.6612 kPa |
| 1,000 mmHg | 133.3224 kPa |
What Each Unit Is
Kilopascals (kPa) — 1,000 pascals. The practical metric working unit for tyre and industrial pressures.
mmHg (mmHg) — the pressure of a one-millimetre column of mercury, or 133.322 pascals. From the mercury barometer; medicine kept it after physics moved to pascals.
A Sense of Scale
Car tyres run at 220–250 kPa- Atmospheric pressure is 101.3 kPa
- Normal blood pressure is 120/80 mmHg
- Atmospheric pressure is 760 mmHg
Doing It in Your Head
Multiply by 15, then divide by 2. That is off by 0.01% — close enough to judge a
distance, a weight or a price, and not close enough to sign off on a drawing.
Exact Mental shortcut 75.0062 mmHg 75 mmHg 750.0616 mmHg 750 mmHg
Precision
The factor 7.50061575846 is rounded. For engineering work carry more digits than the table above, and round only at the end — rounding at each step compounds.
In Code
`javascript
const kilopascalToMmHg = (value) => value * 7.50061575846;
``
Where This Conversion Comes Up
- Weather
- Automotive
- Diving
- Aviation
- HVAC
How Many Decimals Do You Need?
Rounding the factor costs accuracy, and how much depends on the factor. Converting 137 kPa with the factor truncated at each decimal place:
| Decimals kept | Factor | 137 kPa becomes | Error |
|---|---|---|---|
| 0 | 8 | 1,096 | 6.6579% |
| 1 | 7.5 | 1,027.5 | 0.0082% |
| 2 | 7.5 | 1,027.5 | 0.0082% |
| 3 | 7.501 | 1,027.64 | 0.0051% |
| 4 | 7.5006 | 1,027.58 | 0.0002% |
The right number of significant figures is set by your input, not by the converter. If you measured kilopascals to three significant figures, the answer in mmhg is only good to three — writing more digits claims precision the measurement never had.