High-Elevation Airport Pressure Altitude Planner
Pressure altitude planning for the world's high airports — La Paz, Lhasa, Quito, Leadville — where the field starts above many aircraft ceilings.
At La Paz the ambient pressure is ~60% of sea level. Many piston singles and some turboprops carry explicit AFM takeoff/landing pressure-altitude limits — check the envelope before checking the runway.
Formula
⚠️ For flight planning and education only — always verify against your aircraft's POH/AFM, official weather sources and certified instruments. Not for primary navigation or airworthiness decisions.
Disclaimer: This tool is for general informational and estimation purposes only and is not professional financial, tax, accounting or legal advice. All figures are estimates — verify with a qualified professional before making decisions. Read the full disclaimer.
Pressure altitude planning for the world's high airports — La Paz, Lhasa, Quito, Leadville — where the field starts above many aircraft ceilings.
About High-Elevation Airport Pressure Altitude Planner
A handful of commercial airports sit so high that the limiting question is not runway length but whether the airframe and engines are certified to operate there at all. This planner computes field pressure altitude from elevation and QNH, the actual ambient pressure in hectopascals, and your margin against the AFM's maximum takeoff/landing pressure altitude — the envelope check that comes before any performance chart at places like La Paz (13,325 ft) or Daocheng Yading (14,472 ft).
How to use High-Elevation Airport Pressure Altitude Planner
- 1Enter — sensible defaults are pre-filled so you see a worked result immediately.
- 2Read the live results: .
- 3Check the "With your numbers" line to see the formula PA = elev + (1013.25 − QNH) × 27; p_field = 1013.25(1 − 6.876×10⁻⁶·PA)^5.2559 substituted step by step.
- 4Adjust inputs (or flip the unit toggle) until the scenario matches yours, then copy or share the result.
Why use High-Elevation Airport Pressure Altitude Planner?
- ✓Instant, free and private — every calculation runs in your browser, nothing is uploaded
- ✓Built on the published formula PA = elev + (1013.25 − QNH) × 27; p_field = 1013.25(1 − 6.876×10⁻⁶·PA)^5.2559 with sources cited on the page
- ✓At La Paz the ambient pressure is ~60% of sea level. Many piston singles and some turboprops carry explicit AFM takeoff/landing pressure-altitude limits — check the envelope before checking the runway.
- ✓Switch units, tweak any input and watch every result update live
Frequently asked questions
Which airports are the highest in the world?+
Daocheng Yading, China (14,472 ft) currently tops the commercial list, followed by Qamdo Bamda (14,219 ft), Kangding (14,042 ft) and El Alto/La Paz (13,325 ft). In the US, Leadville, Colorado (9,934 ft) leads public-use fields. At all of them, field pressure altitude on a low-QNH day can exceed many aircraft's certified envelopes.
What is a maximum operating pressure altitude limit?+
An AFM limitation defining the highest pressure altitude at which takeoff and landing (and sometimes engine start) are demonstrated and approved — driven by engine ignition/combustion margins, pressurization schedules, stall/buffet boundaries and flight-test scope. Exceeding it isn't a performance gamble; it's operation outside certification.
Why do engines struggle to even start at extreme field elevations?+
Fuel metering and ignition are tuned for a pressure range. At 60% of sea-level pressure, piston engines need careful leaning just to fire and turbines flirt with hung starts because compressor airflow and fuel scheduling drift from design assumptions. Several POHs publish explicit high-altitude start procedures for exactly this case.
Does high QNH meaningfully help at these airports?+
Every hectopascal above 1013.25 buys about 27 ft of pressure altitude — so a strong high (1030 hPa) sits the field ~450 ft 'lower' than standard. That can be the difference between inside and outside an envelope edge, which is why this tool treats QNH as a first-class input rather than assuming standard.
Related Field tools
Sunrise & Sunset Calculator
Exact rise, set, solar noon and day length for any place and date — the NOAA solar equations with the refraction fine print included.
● LiveGolden Hour & Blue Hour Calculator
Tonight's golden hour and blue hour, computed from sun elevation — the photographer's light windows with the angles that define them.
● LiveDay Length Calculator
Hours of daylight for any date and latitude, how fast it's changing, and the swing between your solstices.
● Live