Convert Inches of Mercury to Kilopascals
Instantly convert Inches of Mercury (inHg) to Kilopascals (kPa) with our free online calculator.
Formula: inHg to kPa — multiply by 3.38639
Reference Table
| Inches of Mercury (inHg) | Kilopascals (kPa) |
|---|---|
| 1 | 3.38639 |
| 5 | 16.932 |
| 10 | 33.8639 |
| 25 | 84.6598 |
| 50 | 169.32 |
| 100 | 338.639 |
How to Convert Inches of Mercury to Kilopascals
Formula
To convert Inches of Mercury (inHg) to Kilopascals (kPa): multiply by 3.38639
Step-by-Step
- Start with your value in Inches of Mercury (inHg).
- Multiply by 3.38639 to perform the conversion.
- The result is your value expressed in Kilopascals (kPa).
Conversion Factor
1 inHg = 3.38639 kPa
Reverse Factor
1 kPa = 0.2953 inHg
Worked Example
Convert 25 Inches of Mercury to Kilopascals: 25 inHg = 84.6598 kPa
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 Kilopascal (kPa)
A metric unit of pressure equal to exactly 1,000 pascals (1 kPa = 1,000 N/m²). Kilopascals are the everyday SI pressure unit outside the US: passenger car tire pressure in Europe and Australia is specified in kPa (typically 220-250 kPa cold), building HVAC duct static pressure is in kPa, and the ISO 5198 / IEC 60534 valve standards quote rated pressures in kPa. Weather forecasters quote surface atmospheric pressure in hectopascals (1 kPa = 10 hPa); a typical sea-level barometric reading is 1013 hPa = 101.3 kPa. The kPa is the standard report unit in clinical respiratory physiology (PaCO₂, PaO₂ in some ICUs) and in scientific gauge pressure measurement. Common conversions: kPa to psi is divide by 6.895; kPa to bar is divide by 100; kPa to mmHg is multiply by 7.5006.
Quick Facts
- 1 Inch of Mercury equals 3.38639 Kilopascals
- 1 Kilopascal equals 0.2953 Inches of Mercury
- Inch of Mercury is a unit of pressure
- Kilopascal 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
- The Kilopascal belongs to the metric system
Common Inch of Mercury to Kilopascal Conversions
| Inches of Mercury (inHg) | Kilopascals (kPa) |
|---|---|
| 0.1 | 0.338639 |
| 0.5 | 1.6932 |
| 1 | 3.38639 |
| 2 | 6.77278 |
| 5 | 16.932 |
| 10 | 33.8639 |
| 14.696 | 49.7664 |
| 15 | 50.7959 |
| 20 | 67.7278 |
| 25 | 84.6598 |
| 50 | 169.32 |
| 100 | 338.639 |
| 150 | 507.959 |
| 200 | 677.278 |
| 500 | 1693.19 |
| 1000 | 3386.39 |
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 Kilopascals
The Kilopascal (symbol: kPa) is a unit of pressure. A metric unit of pressure equal to exactly 1,000 pascals (1 kPa = 1,000 N/m²). Kilopascals are the everyday SI pressure unit outside the US: passenger car tire pressure in Europe and Australia is specified in kPa (typically 220-250 kPa cold), building HVAC duct static pressure is in kPa, and the ISO 5198 / IEC 60534 valve standards quote rated pressures in kPa. Weather forecasters quote surface atmospheric pressure in hectopascals (1 kPa = 10 hPa); a typical sea-level barometric reading is 1013 hPa = 101.3 kPa. The kPa is the standard report unit in clinical respiratory physiology (PaCO₂, PaO₂ in some ICUs) and in scientific gauge pressure measurement. Common conversions: kPa to psi is divide by 6.895; kPa to bar is divide by 100; kPa to mmHg is multiply by 7.5006.
It belongs to the metric measurement system.
Kilopascals are commonly used in tire inflation, weather reporting, scuba diving, and engineering.
Why Convert Inches of Mercury to Kilopascals?
Engineers, mechanics, and scientists frequently need to convert pressure between Inches of Mercury and Kilopascals 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 Kilopascals?
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 Kilopascals, multiply by 3.38639. For example, 25 inHg equals 84.6598 kPa.
How many Kilopascals are in 1 Inch of Mercury?
There are 3.38639 Kilopascals in 1 Inch of Mercury.
How many Inches of Mercury are in 1 Kilopascal?
There are 0.2953 Inches of Mercury in 1 Kilopascal.
What is the formula for Inch of Mercury to Kilopascal conversion?
The formula is: multiply by 3.38639. This means 1 inHg = 3.38639 kPa.
Is a Inch of Mercury bigger than a Kilopascal?
No. One Inch of Mercury is smaller than one Kilopascal because 1 inHg equals 3.38639 kPa, which is greater than 1.
When do you need to convert between Inches of Mercury and Kilopascals?
A metric unit of pressure equal to exactly 1,000 pascals (1 kPa = 1,000 N/m²). Inch of Mercury and Kilopascal 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.