Calculate Altitude From Barometric Pressure

Barometric Formula:

\[ h = \frac{R T}{g} \ln\left(\frac{P_0}{P}\right) \]

Gas Constant (R):

J/(mol·K)

Temperature (T):

Gravity (g):

m/s²

Reference Pressure (P₀):

Measured Pressure (P):

Calculated Altitude (h):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What Is The Barometric Formula?

The barometric formula relates atmospheric pressure to altitude, assuming an isothermal atmosphere. It's derived from the ideal gas law and hydrostatic equation, providing a way to calculate altitude from pressure measurements.

2. How Does The Calculator Work?

The calculator uses the barometric formula:

\[ h = \frac{R T}{g} \ln\left(\frac{P_0}{P}\right) \]

Where:

\( h \) — Altitude (m)
\( R \) — Gas constant (8.314 J/(mol·K))
\( T \) — Temperature (K)
\( g \) — Gravitational acceleration (9.80665 m/s²)
\( P_0 \) — Reference pressure at sea level (Pa)
\( P \) — Measured pressure at altitude (Pa)

Explanation: The formula calculates the altitude based on the logarithmic relationship between pressure and height in a static fluid.

3. Importance Of Altitude Calculation

Details: Accurate altitude calculation is crucial for aviation, meteorology, hiking, and various scientific applications where pressure measurements are used to determine elevation.

4. Using The Calculator

Tips: Enter all values in appropriate units. Standard values are provided for R and g, but these can be adjusted for specific conditions. All values must be positive.

5. Frequently Asked Questions (FAQ)

Q1: Why use the barometric formula?
A: It provides a reliable method to estimate altitude from pressure measurements when temperature and gravitational acceleration are known.

Q2: What are typical reference values?
A: Standard sea level pressure is 101325 Pa, and gravitational acceleration is approximately 9.80665 m/s² at sea level.

Q3: How accurate is this calculation?
A: Accuracy depends on the precision of input values and how well conditions match the isothermal atmosphere assumption.

Q4: Are there limitations to this formula?
A: The formula assumes constant temperature and gravity, which may not hold true for large altitude changes or specific atmospheric conditions.

Q5: Can this be used for aviation altitude calculations?
A: While based on similar principles, aviation uses more complex models that account for temperature variations and standard atmospheres.