1. What is Barometric Pressure at Altitude?

Definition: This calculator estimates the atmospheric pressure at a given altitude using the barometric formula.

Purpose: It helps meteorologists, pilots, and outdoor enthusiasts understand how air pressure changes with elevation.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( P \) — Pressure at altitude (Pa)
• \( P_0 \) — Sea level pressure (101325 Pa default)
• \( g \) — Gravitational acceleration (9.81 m/s²)
• \( M \) — Molar mass of air (0.02896 kg/mol)
• \( h \) — Altitude (meters)
• \( R \) — Universal gas constant (8.314 J/mol·K)
• \( T \) — Temperature (Kelvin)

Explanation: The formula models how atmospheric pressure decreases exponentially with altitude.

3. Importance of Barometric Pressure Calculation

Details: Understanding pressure changes is crucial for weather forecasting, aviation, and high-altitude activities.

4. Using the Calculator

Tips: Enter sea level pressure (default 101325 Pa), altitude in meters, and temperature in Kelvin (288.15K = 15°C).

5. Frequently Asked Questions (FAQ)

Q1: Why does pressure decrease with altitude?
A: Pressure decreases because there's less atmospheric mass above you as you go higher.

Q2: What's standard sea level pressure?
A: The international standard is 101325 Pa (1013.25 hPa or 1 atm).

Q3: How does temperature affect the calculation?
A: Warmer air expands, making the pressure decrease more slowly with altitude.

Q4: Can I use Celsius instead of Kelvin?
A: Convert Celsius to Kelvin by adding 273.15 (e.g., 20°C = 293.15K).

Q5: Is this formula accurate for all altitudes?
A: It works well for troposphere altitudes (up to about 11 km). Higher altitudes require more complex models.