AviationCalc is a free collection of calculators and guides for the mathematics of flight. It exists to make that arithmetic visible: not just the answer, but the formula, the units, each step of the working and the assumptions hiding behind it.
What you will find here
- Thirty calculators covering airspeed and Mach number, wind components and the wind triangle, the standard atmosphere, pressure and density altitude, fuel arithmetic, climb, and the basic lift, drag and turn equations. See the full list of calculators.
- Thirty guides that explain each idea in plain language, with a worked example and public references. They are collected under Aviation Guides.
- A methodology page that sets out the constants, unit definitions, rounding and testing behind every result: Calculation Methodology.
Who it is for
The site is written for people learning how these calculations work: student pilots revising for ground school, flight simulator users, engineering and physics students, and anyone curious about why a hot day or a quartering wind changes the numbers. It assumes school-level algebra and trigonometry and explains the aviation terms as it goes.
What AviationCalc is not
AviationCalc is an educational website. It is not an approved flight-planning system, a certified flight computer or electronic flight bag, and it does not replace an aircraft flight manual, official charts, current weather information or the regulations that apply to a flight. The calculators do not know your aircraft. Where a calculation depends on aircraft-specific values, such as a position-error correction, a lift coefficient, a stall speed or a fuel flow, you enter those values yourself and the site never suggests them. The calculators do not recommend fuel reserves, compare a result with any limit, or say whether a takeoff, landing or flight is acceptable. The Disclaimer states this in full.
How the formulas and examples are reviewed
We do not claim professional credentials, licences or endorsements, and nothing on this site should be read as if we did. What we can describe exactly is the checking each calculator goes through before it is published:
- Documented formula. Each calculator’s formula is written out on its page with every variable defined, and traced to a public reference such as the FAA handbooks, NASA’s educational aeronautics pages, the U.S. Standard Atmosphere or NIST’s unit definitions. Referring to those sources does not mean they have reviewed or endorsed this site.
- Automated tests. Every calculator has at least five test cases: normal values, boundary values, deliberately invalid input and unit conversions. Expected results come from hand calculation, published standard-atmosphere tables and exact unit definitions.
- A second implementation. The same formulas are written a second time, separately and in a different programming language, using different formulations where possible. Both versions must agree to one part in a million on every test case.
- Generated examples. The worked example on each calculator page is produced by the calculator itself, so the example cannot drift away from what the calculator actually does.
- Editorial checks. Guides are checked so that every figure in them matches the calculators, sources are limited to a fixed list of public references, and no aircraft-specific limits or operating advice appear.
Found a mistake?
Corrections are welcome and taken seriously. If a result looks wrong, tell us the calculator, the values you entered, the result you saw and the result you expected, using the contact form. Confirmed errors are fixed and a test case is added so the same error cannot return.