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Convert Inches of Mercury to Kilopounds per Square Inch

Instantly convert Inches of Mercury (inHg) to Kilopounds per Square Inch (ksi) with our free online calculator.

Reviewed by Christopher FloiedUpdated

Formula: inHg to ksimultiply by 4.9115e-4

Reference Table

Inches of Mercury (inHg)Kilopounds per Square Inch (ksi)
10.000491154
50.00245577
100.00491154
250.0122789
500.0245577
1000.0491154

How to Convert Inches of Mercury to Kilopounds per Square Inch

Formula

To convert Inches of Mercury (inHg) to Kilopounds per Square Inch (ksi): multiply by 4.9115e-4

Step-by-Step

  1. Start with your value in Inches of Mercury (inHg).
  2. Multiply by 4.9115e-4 to perform the conversion.
  3. The result is your value expressed in Kilopounds per Square Inch (ksi).

Conversion Factor

1 inHg = 0.000491154 ksi

Reverse Factor

1 ksi = 2036.02 inHg

Worked Example

Convert 25 Inches of Mercury to Kilopounds per Square Inch: 25 inHg = 0.0122789 ksi

About Inch of Mercury (inHg)

A pressure unit defined as the pressure exerted by a 1-inch column of mercury at the standard density of mercury (0 °C) and the standard acceleration of gravity (≈ 3,386.389 Pa per NIST SP 811). Inches of mercury are the primary unit in US aviation for altimeter settings (the QNH datum is reported in inHg in METAR weather observations — "Altimeter 30.12 inHg" means 30.12 inHg corrected to mean sea level), US barometric weather reporting on consumer indoor weather stations and TV weather graphics, HVAC and refrigeration duct/return static pressure (often quoted as fractions of an inHg, e.g., 0.25 inHg = ~62 Pa), and some legacy automotive vacuum gauges measuring intake-manifold vacuum below atmospheric (a healthy engine reads ~18-22 inHg of vacuum at idle). Standard sea-level atmospheric pressure is 29.92 inHg = 1013.25 hPa = 101.325 kPa.

About Kilopound per Square Inch (ksi)

An imperial unit of pressure equal to exactly 1,000 psi (≈ 6.895 MPa). KSI is the standard US unit for reporting material strength: structural-steel yield (A36 = 36 ksi, A992 W-shapes = 50 ksi, A572-Gr50 plate = 50 ksi, A514 quenched-tempered = 100 ksi), bolt-grade tensile strength (SAE Grade 5 = 120 ksi, Grade 8 = 150 ksi, ASTM A325 = 105-120 ksi, A490 = 150 ksi), aluminum aerospace alloys (7075-T6 ultimate = ~83 ksi), and the S-N fatigue curves in MMPDS / ASME Section VIII Division 3. US structural codes (AISC Steel Construction Manual, AASHTO LRFD Bridge Design), aerospace stress reports, and oil-and-gas casing specifications (API 5CT) all express allowables and yield in ksi. When cross-referencing US alloys against international material databases (typically MPa), the conversion ksi × 6.895 → MPa is essentially universal.

Quick Facts

  • 1 Inch of Mercury equals 0.000491154 Kilopounds per Square Inch
  • 1 Kilopound per Square Inch equals 2036.02 Inches of Mercury
  • Inch of Mercury is a unit of pressure
  • Kilopound per Square Inch is a unit of pressure
  • This conversion is commonly used in tire inflation, weather reporting, scuba diving, and engineering
  • The Inch of Mercury belongs to the imperial system

Common Inch of Mercury to Kilopound per Square Inch Conversions

Inches of Mercury (inHg)Kilopounds per Square Inch (ksi)
0.10.0000491154
0.50.000245577
10.000491154
20.000982308
50.00245577
100.00491154
14.6960.007218
150.00736731
200.00982308
250.0122789
500.0245577
1000.0491154
1500.0736731
2000.0982308
5000.245577
10000.491154

Understanding Inches of Mercury

The Inch of Mercury (symbol: inHg) is a unit of pressure. A pressure unit defined as the pressure exerted by a 1-inch column of mercury at the standard density of mercury (0 °C) and the standard acceleration of gravity (≈ 3,386.389 Pa per NIST SP 811). Inches of mercury are the primary unit in US aviation for altimeter settings (the QNH datum is reported in inHg in METAR weather observations — "Altimeter 30.12 inHg" means 30.12 inHg corrected to mean sea level), US barometric weather reporting on consumer indoor weather stations and TV weather graphics, HVAC and refrigeration duct/return static pressure (often quoted as fractions of an inHg, e.g., 0.25 inHg = ~62 Pa), and some legacy automotive vacuum gauges measuring intake-manifold vacuum below atmospheric (a healthy engine reads ~18-22 inHg of vacuum at idle). Standard sea-level atmospheric pressure is 29.92 inHg = 1013.25 hPa = 101.325 kPa.

It belongs to the imperial measurement system.

Inches of Mercury are commonly used in tire inflation, weather reporting, scuba diving, and engineering.

Understanding Kilopounds per Square Inch

The Kilopound per Square Inch (symbol: ksi) is a unit of pressure. An imperial unit of pressure equal to exactly 1,000 psi (≈ 6.895 MPa). KSI is the standard US unit for reporting material strength: structural-steel yield (A36 = 36 ksi, A992 W-shapes = 50 ksi, A572-Gr50 plate = 50 ksi, A514 quenched-tempered = 100 ksi), bolt-grade tensile strength (SAE Grade 5 = 120 ksi, Grade 8 = 150 ksi, ASTM A325 = 105-120 ksi, A490 = 150 ksi), aluminum aerospace alloys (7075-T6 ultimate = ~83 ksi), and the S-N fatigue curves in MMPDS / ASME Section VIII Division 3. US structural codes (AISC Steel Construction Manual, AASHTO LRFD Bridge Design), aerospace stress reports, and oil-and-gas casing specifications (API 5CT) all express allowables and yield in ksi. When cross-referencing US alloys against international material databases (typically MPa), the conversion ksi × 6.895 → MPa is essentially universal.

It belongs to the imperial measurement system.

Kilopounds per Square Inch are commonly used in tire inflation, weather reporting, scuba diving, and engineering.

Why Convert Inches of Mercury to Kilopounds per Square Inch?

Engineers, mechanics, and scientists frequently need to convert pressure between Inches of Mercury and Kilopounds per Square Inch when working with different measurement standards. Tire pressure, blood pressure readings, weather barometric measurements, and industrial process specifications may all use different pressure units depending on the region or discipline. Reliable conversion prevents equipment misuse and ensures safety.

Frequently Asked Questions

How do I convert Inches of Mercury to Kilopounds per Square Inch?

A pressure unit defined as the pressure exerted by a 1-inch column of mercury at the standard density of mercury (0 °C) and the standard acceleration of gravity (≈ 3,386. To convert Inches of Mercury to Kilopounds per Square Inch, multiply by 4.9115e-4. For example, 25 inHg equals 0.0122789 ksi.

How many Kilopounds per Square Inch are in 1 Inch of Mercury?

There are 0.000491154 Kilopounds per Square Inch in 1 Inch of Mercury.

How many Inches of Mercury are in 1 Kilopound per Square Inch?

There are 2036.02 Inches of Mercury in 1 Kilopound per Square Inch.

What is the formula for Inch of Mercury to Kilopound per Square Inch conversion?

The formula is: multiply by 4.9115e-4. This means 1 inHg = 0.000491154 ksi.

Is a Inch of Mercury bigger than a Kilopound per Square Inch?

Yes. One Inch of Mercury is larger than one Kilopound per Square Inch because 1 inHg equals 0.000491154 ksi, which is less than 1.

When do you need to convert between Inches of Mercury and Kilopounds per Square Inch?

An imperial unit of pressure equal to exactly 1,000 psi (≈ 6. Inch of Mercury and Kilopound per Square Inch are both pressure units, so conversion comes up whenever one source of information uses one unit and another uses the other — a classic cross-reference challenge in engineering, trade, travel, and everyday life.

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