Atmospheric Pressure by Address Calculator

An atmospheric pressure by address calculator estimates air pressure at a location using its elevation; an address alone is not enough unless the tool can geocode it and obtain ground height. Enter the location’s elevation above sea level to estimate standard-atmosphere pressure, usually returned in pascals, kilopascals, hectopascals, or inches of mercury.

Formula

This calculator uses the standard-atmosphere barometric formula for the troposphere: p = p₀ × (1 − Lh/T₀)^5.25588. Here, p is estimated station pressure in kilopascals (kPa), p₀ is standard sea-level pressure, 101.325 kPa, h is elevation above mean sea level in metres (m), L is the standard temperature lapse rate, 0.0065 kelvin per metre, and T₀ is standard sea-level temperature, 288.15 K. The exponent is derived from the standard-atmosphere constants.

The output conversions are 1 kPa = 10 hPa and 1 kPa ≈ 0.2952998 inches of mercury (inHg). The elevation input is limited to 0–11,000 m because this simple formula represents the standard atmosphere in the lower atmospheric layer; it is not a universal model for higher altitudes or all weather conditions. The calculator estimates pressure from elevation, not from an address lookup.

Worked Example

With the default elevation of 0 m:

1. Compute the temperature factor: 1 − (0.0065 × 0 / 288.15) = 1.
2. Raise it to the stated exponent: 1^5.25588 = 1.
3. Multiply by standard sea-level pressure: 101.325 × 1 = 101.325 kPa, which rounds to 101.33 kPa.
4. Convert the unrounded pressure: 101.325 × 10 = 1013.3 hPa to one decimal place, and 101.325 × 0.2952998 = 29.92 inHg to two decimal places.

These are model outputs for the default sea-level elevation, not a live reading of today’s weather.

Can You Calculate Pressure From an Address?

Yes, if a service first translates the address into coordinates and then looks up or estimates the elevation. The pressure calculation itself mainly needs elevation. Addresses can be ambiguous, buildings can span different heights, and elevation databases may represent terrain rather than a building’s floor or rooftop. Check that the selected result is the intended place and that its elevation is stated relative to mean sea level.

This page’s calculator does not connect to an address database. Find the elevation from a reliable map, a digital elevation model, a surveyed source, or a GPS device, then enter it in metres. For a reading at a particular indoor floor or rooftop, add that height to the terrain elevation where relevant. For rough estimates, rounding elevation to the nearest metre is generally more precision than the weather model warrants.

What the Pressure Number Means

The result is an estimate of station pressure: the weight of the atmosphere above a location, expressed as pressure at that elevation. Pressure normally decreases as elevation increases because there is less air overhead. As an illustration, an elevation near 1,000 m produces a standard-atmosphere estimate of about 90.0 kPa, rather than the sea-level value of 101.325 kPa.

Do not confuse station pressure with a weather report’s sea-level pressure. Weather services commonly adjust observed pressure to a sea-level reference so readings from places at different elevations can be compared. That adjusted number is not the pressure physically measured at a high-altitude station. For aviation, weather analysis, or instrument calibration, use the specific pressure definition required by the application.

Why a Calculator Estimate Differs From a Barometer

The standard atmosphere is a reference model, not a forecast. Actual pressure changes with weather systems, temperature, humidity, and the changing mass of air above a location. A local barometer can therefore report a different value, even when the elevation is known accurately. The calculator does not use current weather observations or account for local atmospheric conditions.

• Elevation error: entering feet as though they were metres makes the result substantially wrong. Convert feet to metres by multiplying by 0.3048; convert metres to feet by multiplying by about 3.28084.
• Wrong elevation reference: use elevation above mean sea level, not height above the street, a building floor, or a nearby river.
• Reference mismatch: compare station pressure with station pressure, not with a sea-level-adjusted weather value.
• Excess precision: extra decimal places do not make a model more accurate than its assumptions or elevation data.

When to Use This Estimate—and Its Limits

The formula is useful for understanding how altitude affects pressure, checking an approximate value, or supplying an initial estimate when no observation is available. It is not a substitute for a calibrated pressure sensor when an accurate current measurement matters. At elevations below sea level, the same physical relationship can be useful, but this calculator accepts only nonnegative elevations; obtain a suitable model or measurement for that case.

Above 11,000 m, atmospheric models require additional layers and assumptions. Even within the input range, the result can diverge from actual conditions. If a task specifies a particular atmosphere, altitude convention, or pressure reference, follow that specification rather than assuming this standard-atmosphere estimate is interchangeable.

Frequently Asked Questions

Can I enter an address directly?
No. This calculator requires elevation in metres. Use an address-to-elevation lookup elsewhere, verify the location and elevation, and enter that value here.

What is normal atmospheric pressure at sea level?
The standard reference is 101.325 kPa, equal to 1013.25 hPa or about 29.92 inHg. Actual sea-level pressure varies with weather.

Does elevation increase or decrease air pressure?
Pressure generally decreases as elevation rises because less atmosphere lies above the location. The formula estimates that change under standard-atmosphere assumptions.

Why is my calculator result different from a weather app?
A weather app may show current observed pressure or pressure adjusted to sea level. This calculator estimates standard-atmosphere station pressure from elevation alone.

How do I convert elevation from feet to metres?
Multiply the elevation in feet by 0.3048. For example, 3,280.84 ft is approximately 1,000 m. Enter the converted value, not the original feet figure.

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in h | Elevation | m | 0 | 0 | 11000
out p | Estimated pressure | kPa | 101.325 * (1 - 0.0065 * h / 288.15) ^ 5.25588 | 2
out hp | Estimated pressure | hPa | p * 10 | 1
out mhg | Estimated pressure | inHg | p * 0.2952998 | 2