Unit Converter
Convert From Hectopascals (hPa) to Inches of Mercury (inHg) and Vice Versa
Hectopascals ↔ Inches of Mercury
Type in either hPa or inHg — it’ll convert to the other automatically!
🎯 Interactive Converter
1013 hPa = 29.91 inHg
🌬️ What is a Hectopascal (hPa)?
A hectopascal is a metric unit of pressure widely used in **meteorology** and **aviation**. It's equivalent to 100 pascals, and commonly used to measure **atmospheric pressure**. Standard sea level pressure is about 1013.25 hPa.
🌡️ What is Inches of Mercury (inHg)?
Inches of mercury (inHg) is an imperial unit of pressure, traditionally used in **barometers** and **U.S. aviation altimeters**. It measures how high the pressure can push a column of mercury — standard pressure is 29.92 inHg.
🧠 Quick Comparison
| Unit | Equivalent | Used In |
|---|---|---|
| 1 hPa | 0.02953 inHg | Weather reports, METARs, aviation (Europe, Asia) |
| 1 inHg | 33.8639 hPa | Altimeters, barometers (U.S., Canada) |
🧮 How to Convert
hPa to inHg: inHg = hPa × 0.02953
inHg to hPa: hPa = inHg × 33.8639
Example:
1013.25 hPa × 0.02953 = 29.92 inHg
💡 Pro Tip
In aviation, **set the altimeter** to the local pressure: 1013.25 hPa (Europe) or 29.92 inHg (U.S.). They both mean standard sea level pressure.
🎉 Did You Know?
The "inHg" unit dates back to 1643 when Evangelista Torricelli used a tube of mercury to discover **barometric pressure**. Even today, aircraft altimeters and barometers still use this legacy unit!
🌍 Real-World Pressure Examples
- 980 hPa – Low pressure system (stormy weather)
- 1013.25 hPa – Standard sea-level pressure
- 1050 hPa – High pressure (clear skies)
- 29.92 inHg – Standard pressure on altimeters (U.S.)
📊 hPa to inHg Conversion Chart
| hPa | inHg |
|---|---|
| 980 | 28.94 |
| 1000 | 29.53 |
| 1013.25 | 29.92 |
| 1020 | 30.09 |
| 1050 | 30.99 |
📜 Timeline: Pressure Measurement History
- 1643: Torricelli invents the barometer with mercury
- 1900s: Inches of mercury standard in aviation altimeters
- Modern era: hPa (hectopascals) adopted globally via SI units
🌐 When to Use hPa vs inHg
- 🛫 inHg: Aircraft altimeters in U.S., barometric forecasts
- ☁️ hPa: Weather stations and aviation worldwide (METAR, TAF)
- 🧮 Quick Tip: Multiply hPa × 0.02953 to get inHg instantly