This page converts inches of mercury into kilopounds per square inch using the factor 0.0004911541996, and shows the reverse figure alongside it. Both units measure pressure, which is why one number does the whole job.
One thousand psi; the unit US steel and alloy strengths are quoted in. US aviation and weather altimeter setting unit.
Gauge versus absolute. A tyre gauge reading 32 psi means 32 psi above atmospheric, which is about 46.7 psi absolute. Converting the number is straightforward; remembering which zero it was measured from is where the mistakes happen. N/mm² and MPa are the same size, so a drawing quoting either is quoting the same stress. Two tables follow: rounded steps for quick lookup, and a set of real reference quantities converted into kilopounds per square inch, which is usually more useful than the bare number.
The formula
inches of mercury- The amount you are converting, in inches of mercury
0.000491154199634- The exact number of kilopounds per square inch in one inch of mercury
kilopounds per square inch- The converted result
How it works, step by step
- Enter the value in inches of mercury.
- It is multiplied by 0.000491154199634, the exact factor between the two units.
- The answer is shown in kilopounds per square inch, with the reverse conversion beneath it.
- Check the reference table if you want a figure of comparable size.
Worked examples
Blood pressure, systolic: 4.72 inHg in kilopounds per square inch
At 4.72 inHg (blood pressure, systolic), the same quantity in kilopounds per square inch is 4.72 × 0.000491154 = 0.00231825 ksi. One inch of mercury is 0.000491154 kilopounds per square inch, so the numbers shrink as expected.
A steam boiler: 295 inHg in kilopounds per square inch
Take a steam boiler, roughly 295 inHg. The conversion is a single multiplication — 295 × 0.000491154 — giving 0.14489 ksi. Because the relationship is proportional, doubling the input doubles the answer to 0.289781 ksi.
How to read your score
Frequently asked questions
How many kilopounds per square inch are in one inch of mercury?
Exactly 0.000491154199634. Every figure on this page is that one number multiplied by your input, so the only rounding is at the display step.
What is the formula to convert inches of mercury to kilopounds per square inch?
kilopounds per square inch = inches of mercury × 0.000491154199634. Reversed, inches of mercury = kilopounds per square inch ÷ 0.000491154199634, which is the same as multiplying by 2036.02046108.
Which is the bigger unit, the inch of mercury or the kilopound per square inch?
The kilopound per square inch. One inch of mercury is only 0.000491154 of a kilopound per square inch, so it takes 2036.02 inches of mercury to make one kilopound per square inch.
What does this quantity actually measure?
Both units measure pressure. That is why a single factor is enough: there is no temperature offset and no material property involved, unlike conversions that cross between different quantities.
What is a inch of mercury?
US aviation and weather altimeter setting unit.
What is a kilopound per square inch?
One thousand psi; the unit US steel and alloy strengths are quoted in.
Why does my answer differ from another converter?
Almost always because the other tool rounded the factor before multiplying. This page keeps full double precision through the calculation and rounds only for display, and it prints the factor it used so you can see where any difference came from.
Is there a quick way to do inHg to ksi in my head?
Plenty of people do this in their head: divide by 2000 instead of using the exact factor 0.0004911541996. At 100 that shortcut gives 0.05 kilopounds per square inch, off by 0.0008846 kilopounds per square inch or about 1.80%. Fine for a rough estimate, not fine for anything you are cutting to size or dosing.
Inches Of Mercury to kilopounds per square inch reference tables
| Inches Of Mercury | Kilopounds Per Square Inch |
|---|---|
| 0.5 inHg | 0.000245577 ksi |
| 1 inHg | 0.000491154 ksi |
| 2 inHg | 0.000982308 ksi |
| 3 inHg | 0.00147346 ksi |
| 5 inHg | 0.00245577 ksi |
| 10 inHg | 0.00491154 ksi |
| 20 inHg | 0.00982308 ksi |
| 25 inHg | 0.0122789 ksi |
| 50 inHg | 0.0245577 ksi |
| 75 inHg | 0.0368366 ksi |
| 100 inHg | 0.0491154 ksi |
| 250 inHg | 0.122789 ksi |
| 500 inHg | 0.245577 ksi |
| 1000 inHg | 0.491154 ksi |
| 5000 inHg | 2.45577 ksi |
Exact factor: 1 inch of mercury = 0.000491154199634 kilopounds per square inch.
| Quantity | inHg | ksi |
|---|---|---|
| Sea-level air | 29.92 inHg | 0.0147 ksi |
| A car tyre | 65.15 inHg | 0.032 ksi |
| Blood pressure, systolic | 4.724 inHg | 0.00232 ksi |
| A bicycle tyre | 183.2 inHg | 0.09 ksi |
| A domestic water main | 118.1 inHg | 0.05802 ksi |
| A steam boiler | 295.3 inHg | 0.145 ksi |
Published reference values, converted with the same factor this page uses.