Hectopascal to Atmosphere (std) Converter
Convert Hectopascal (hPa) to Atmosphere (std) (atm) instantly. 1 hPa = 0.000987 atm.
Pressure Converter
29 units available
1 hPa = 0.000987 atm
Formula:
atm = hPa × 0.0009869233With your value: 1 hPa = 0.00098692 atm
Other Hectopascal to Atmosphere (std) conversions
Hectopascal to Atmosphere (std) Conversion Table
| Hectopascal (hPa) | Atmosphere (std) (atm) |
|---|---|
| 0.5 | 0.000493 |
| 1 | 0.000987 |
| 2 | 0.001974 |
| 5 | 0.004935 |
| 10 | 0.009869 |
| 15 | 0.014804 |
| 20 | 0.019738 |
| 25 | 0.024673 |
| 50 | 0.049346 |
| 100 | 0.098692 |
| 250 | 0.246731 |
| 500 | 0.493462 |
| 1000 | 0.986923 |
Atmosphere (std) to Hectopascal Conversion Table
| Atmosphere (std) (atm) | Hectopascal (hPa) |
|---|---|
| 0.5 | 506.625 |
| 1 | 1,013.25 |
| 2 | 2,026.5 |
| 5 | 5,066.25 |
| 10 | 10,132.5 |
| 15 | 15,198.75 |
| 20 | 20,265 |
| 25 | 25,331.25 |
| 50 | 50,662.5 |
| 100 | 101,325 |
| 250 | 253,312.5 |
| 500 | 506,625 |
| 1000 | 1,013,250 |
Where these values come from
Every factor on this page is traced to the document that defines it. See the full provenance dataset or our methodology.
Hectopascal (hPa)
Pressure
Derived from the pascal (1 Pa = 1 N/m²). The standard atmosphere is exactly 101 325 Pa.
Source: NIST Special Publication 811, Guide for the Use of the International System of Units
National Institute of Standards and Technology (US) · Reviewed 2026-07-01
Atmosphere (std) (atm)
Pressure
The standard atmosphere is exactly 101 325 Pa.
Source: Units accepted for use with the SI, SI Brochure Table 8
Bureau International des Poids et Mesures · Reviewed 2026-07-01
How to Convert Hectopascal to Atmosphere (std)
To convert from Hectopascal (hPa) to Atmosphere (std) (atm), multiply the value by 0.0009869233.
Formula: atm = hPa × 0.0009869233
Reverse: hPa = atm × 1,013.25
Step-by-Step Example
- Start with your value in Hectopascal. For example: 5 hPa
- Multiply by the conversion factor: 5 x 0.0009869233
- The result is: 0.004935 atm
About Hectopascal
The hectopascal (hPa) is a unit of pressure and stress. One hectopascal equals 100 pascals. UnitConvertLab converts it against every other pressure unit using this exact definition, so results are reproducible to full double precision rather than rounded lookup tables.
Common uses: pressure calculations, engineering and science, education.
About Atmosphere (std)
One standard atmosphere equals 101,325 Pascals and represents the average air pressure at sea level.
Common uses: diving, weather, chemistry.
Frequently Asked Questions
How many Atmosphere (std) are in 1 Hectopascal?
There are exactly 0.0009869233 Atmosphere (std) in 1 Hectopascal. This means the conversion factor from Hectopascal to Atmosphere (std) is 0.0009869233.
What is the formula to convert Hectopascal to Atmosphere (std)?
The formula to convert Hectopascal to Atmosphere (std) is: atm = hPa × 0.0009869233. For example, to convert 10 Hectopascal to Atmosphere (std), you would multiply 10 by 0.0009869233.
What is a Hectopascal?
The hectopascal (hPa) is a unit of pressure and stress. One hectopascal equals 100 pascals. UnitConvertLab converts it against every other pressure unit using this exact definition, so results are reproducible to full double precision rather than rounded lookup tables.
What is a Atmosphere (std)?
One standard atmosphere equals 101,325 Pascals and represents the average air pressure at sea level.
What are the common uses of Hectopascal?
The Hectopascal is commonly used in pressure calculations, engineering and science, education.
Related Pressure Conversions
Cite this page
UnitConvertLab. (2026). Hectopascal to Atmosphere (std) converter. UnitConvertLab. Retrieved from https://unitconvertlab.com/convert/hectopascal-to-atmosphere