Runway Length Calculator
Compare approved AFM/POH aircraft performance required distances against declared runway distances (TORA, TODA, ASDA, LDA) to verify planning margins.
Use the Runway Length Calculator
AFM/POH Required Distances (ft)
Values must be retrieved from the approved Aircraft Flight Manual / POH performance charts for current conditions.
Published Declared Runway Distances (ft)
From airport Chart Supplement, Jeppesen, or official AIP declared distances table.
Safety Buffer & Chart Lookup Reference
Note: This DA is an environmental approximation for entering AFM/POH charts: DA ≈ PA + 120 × (OAT − ISA). It is not an aircraft performance output.
Declared Distance Runway Margins 0% Buffer Applied
| Operation | Declared Available | AFM Required + Buffer | Margin (ft) | Margin (%) |
|---|
FAA Declared Distances & Operating Principles
The physical length of runway declared available and suitable for the ground run of an airplane taking off.
TORA plus the length of any declared clearway. Compare it with the applicable total takeoff distance from approved aircraft data.
TORA plus the length of any declared stopway. Used to assess distance required to abort a takeoff.
Runway declared available and suitable for ground run of an airplane landing. Excludes displaced thresholds.
Preflight planning limitations:
- Pilots in command must obtain reliable information concerning runway lengths and takeoff/landing distance data from the approved AFM/POH.
- Unapproved generic multipliers (e.g. fixed obstacle ratios or power-law weight exponents) must never replace certified flight manual data.
- Consider surface type (turf, asphalt), runway gradient, braking condition, wind gusts, and local density altitude when consulting POH tables.
Primary references: FAA AIP — declared distances, FAA Fly Safe — aircraft performance, and FAA Airplane Flying Handbook, Chapter 6.
Privacy: Values entered here are calculated in your browser and are not sent to a runway-calculation endpoint.
Summary
Compare approved AFM/POH aircraft performance required distances against declared runway distances (TORA, TODA, ASDA, LDA) to verify planning margins.
How it works
- Look up required takeoff ground run, total takeoff distance, accelerate-stop distance (if applicable), and landing distance in your aircraft POH/AFM for current weight and weather.
- Enter published declared distances for the active runway: Takeoff Run Available (TORA), Takeoff Distance Available (TODA), Accelerate-Stop Distance Available (ASDA), and Landing Distance Available (LDA).
- Enter a planning buffer only when required by your operating rules, approved guidance, or personal minimums; the calculator does not recommend a universal percentage.
- Review the calculated buffered requirements, remaining margins in feet, and margin percentage relative to published declared runway length.
Use cases
- Pre-flight runway margin checks comparing POH required distances to published declared distances.
- Evaluating whether aircraft takeoff run fits within Takeoff Run Available (TORA).
- Comparing total takeoff distance over obstacles against Takeoff Distance Available (TODA).
- Assessing accelerate-stop distance requirements against ASDA for multi-engine operations.
- Verifying landing distance required against published Landing Distance Available (LDA).
- Computing field density altitude approximation for entering AFM/POH performance tables.