# Conversion to sea-level pressure Calculator

## Calculates the sea-level pressure from the atmospheric pressure, temperature and altitude at the present location. | |||

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- Purpose of use
- Home-made weather station.
- Comment/Request
- A big "thank you!" to "2020/05/19 06:51 Male / 50 years old level / An engineer / Very / " -- that code did indeed help a great deal. Thanks too, to whomever researched the equation. I now have relative humidity to within a millibar (hPa) or so. Result!

[1] 2020/09/23 21:30 Male / 60 years old level or over / A retired person / Very /

- Purpose of use
- conversion of pressure sensor readout
- Comment/Request
- thanks for the formula!

[2] 2020/07/03 17:47 Male / 30 years old level / A teacher / A researcher / Very /

- Purpose of use
- Want to understand the BME280 and relevant information for my Arduino weather station. Took some time to get the correct formula in Sketch due to my programming level. Hopefully this will help others:

float p0 = ((pres/100) * pow(1 - (0.0065 * h / (temp + 0.0065 * h + 273.15)), -5.257));

[3] 2020/05/19 06:51 Male / 50 years old level / An engineer / Very /

- Purpose of use
- Check own calculations made using hyposometric equation
- Comment/Request
- The ability to use different units would be nice.

[4] 2020/03/30 06:21 Female / 20 years old level / High-school/ University/ Grad student / Useful /

- Purpose of use
- Weather observation.
- Comment/Request
- Please provide an option to input data in imperial units (degrees Fahrenheit, inHg, feet). Thank you.

[5] 2020/03/23 03:43 Male / 20 years old level / Others / Useful /

- Purpose of use
- Building a ESP32 Web Server with BME280 – Advanced Weather Station

[6] 2020/03/21 23:05 Male / 60 years old level or over / High-school/ University/ Grad student / Very /

- Purpose of use
- Reset weather station

[7] 2020/01/05 02:13 Male / 60 years old level or over / A retired person / Very /

- Purpose of use
- school assignment

[8] 2019/12/07 03:24 Male / Under 20 years old / High-school/ University/ Grad student / Very /

- Purpose of use
- Develop a personal weather station (PWS)
- Comment/Request
- I am developing a personal weather station (PWS) using a Particle Photon, the SHT31 temperature and humidity sensor, the BMP388 barometric pressure sensor, and the Davis anemometer for Vantage Pro2, the PWS is reporting the barometric pressure to Wunderground, and Wunderground requires this to be at SeaLevel, which means no mater at what altitude the PWS is, the barometric pressure always will be the same, or 29.62 inHg, here is where this formula solved my problem. Of course, I divided the result by 33.8639. Bingo! Just in case, here is the formula: seaLevel = (hPa * pow(1 - (0.0065*altitude) / (bmp.temperature + (0.0065 * altitude) + 273.15),-5.257 )) / 33.8639;

Thanks a lot!

[9] 2019/11/29 17:06 Male / 50 years old level / A teacher / A researcher / Very /

- Purpose of use
- Hobby

[10] 2019/10/16 04:23 Male / 60 years old level or over / A retired person / Useful /

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