Altitude & Atmospheric Pressure

Welcome to pressure folks, where atmospheric pressure is calculated based on height above or below sea level. I worked for awhile to get these calculators. I tried several times to make my own, but I live at a very odd altitude. I get very strange barometric pressure readings at times. Made it very difficult to produce accurate calculators so I gathered these from around the network, they are accurate as they can be. Some tell you what your pressure should be; some tell you the percents of pressure on you at a given altitude. Others tell you information about the city you live in, such as geographical information, height above sea level, and population, and geographic coordinates on a map. Enjoy the pressure.

Barometric Pressure Adjustment Standard Calculator, Go HERE

Above Sea Level Barometer Reading,
Temperature Correction Calculator

This calculator requires the use of Javascript enabled and capable browsers. This script determines the error in an observed barometer reading, based on elevation above (or below) sea level of the barometer and the outside air temperature. ; the higher the elevation, the lower the pressure. With the barometer at elevations above sea level, the correction should be added since it is a negative value; below sea level, the value is also added but the value is positive. The default values are typical for the general lower desert area of Southern California. If you wish to show below sea level changes, just use a negative number for the appropriate elevation. To use the calculator, enter the elevation of the barometer, the air temperature (OAT) and the known and observed barometer reading, in any of the possible designations, then click on Calculate. Actual calculations are done on inches of mercury, feet and degrees F. Results are yielded in both inches of mercury and millibars (mb). The metric unit hPa (hectoPascal) is for all practical purposes, identical to the pressure unit designated as millibars; in reality, there is a very small difference, but the scientific community accepts them as the same. There is also an elevation correction chart, for a given temperature, below the calculator.

The standard value for atmospheric pressure at sea level (ATM) is equal to:

1 atm = 29.92 in Hg (inches of mercury)
1 atm = 760 mm Hg (millimeters of mercury)
1 atm = 1013.20 millibars
1 atm = 14.7 psi (pounds force per square inch)
1 atm = 1013.20 hPa (hectopascals)

To further complicate matters, there are actually 2 values for an atmosphere. The first is generally called "standard" and the other is termed as "scientific". These are based on standard atmosphere calculations. Other pressure correction calculators are available on the world wide web.

Required Data Entry
Air Temperature Degrees               C              F 
Elevation Of Barometer ASL      Meters         Feet 
Observed Barometer Reading Inches Hg  Millibars 
Calculated Results
Actual Barometer Correction inches of mercury
Rounded Barometer Correction inches of mercury
Actual Barometer Corrected inches of mercury
Rounded Barometer Corrected inches of mercury
Actual Barometer Correction millibars
Rounded Barometer Correction millibars
Actual Barometer Corrected millibars
Rounded Barometer Corrected millibars

Correction For Elevation In Inches Hg
Per 100 Foot Difference In Elevation

To be added to barometer readings when above the datum plane or
subtracted from barometer readings when below the datum plane.

Temperature, F
0 10 20 30 40 50 60 70 80 90
0 .122 .119 .117 .114 .112 .110 .108 .106 .104 .102
1000 .118 .115 .113 .110 .108 .106 .104 .102 .100 .098
2000 .113 .110 .108 .106 .104 .102 .100 .098 .096 .094
3000 .108 .106 .104 .102 .100 .098 .096 .094 .092 .090
4000 .104 .102 .100 .098 .096 .094 .092 .090 .088 .086
5000 .100 .098 .096 .094 .092 .090 .088 .086 .084 .082
6000 .096 .094 .092 .090 .088 .086 .084 .082 .081 .080
7000 .093 .091 .089 .087 .085 .084 .082 .080 .079 .078

Version 2.7.8

Your Atmospheric Pressure

Not Sure of Location Elevation Enter the name of the place you want to look up, make sure you press back once you find the location elevation.

For example, enter "cambridge, ma" to look up Cambridge, Massachusetts. If you enter just "cambridge", you will get information on all towns called Cambridge.

This server contains mostly information on locations within the US.

This data is considered current


For Populations if the above doesn't give you that information, and thats what your seeking Input information below to get the most accurate information, Thanks.

Search for a Place in the US

Name: State (optional):
or a 5-digit zip code:

Length Equivalents
First, type the number you wish converted here:
Then, click radio buttons for desired conversion:
From: Centimeters
To: Centimeters

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