The Toolbox — Calculators
Avionics, Aerospace & Flight
Density altitude, true airspeed, crosswind component, standard rate turn, time/speed/distance, weight & balance, antenna length, HAM antenna, drone flight time, rocket motor classification, and battery runtime calculators.
Density Altitude Calculator
FAA-H-8083-25 approximation: DA = Pressure Altitude + 120 × (OAT − ISA Temperature).
Higher density altitude reduces engine power, propeller efficiency, and lift — increasing takeoff distance and reducing climb performance.
True Airspeed (TAS) Estimator
Rule-of-thumb estimate: TAS ≈ CAS + 2% of CAS per 1,000 ft of pressure altitude, under standard temperature.
This approximation assumes standard (ISA) temperature and is most accurate below about 10,000 ft. For non-standard temperatures or higher altitudes, use an E6B flight computer or the aircraft's performance charts.
Crosswind & Headwind Component Calculator
Resolves reported wind into headwind/tailwind and crosswind components for a given runway.
Wind direction and speed as reported in the METAR/ATIS (magnetic). Runway number is multiplied by 10 to get magnetic heading — e.g. Runway 27 = 270°.
Standard Rate Turn Calculator
A standard rate turn is 3°/second — a full 360° turn always takes 2 minutes, regardless of airspeed.
Bank angle uses the rule of thumb TAS/10 + 7. Above roughly 250 kt TAS, many operators fly a half-standard-rate turn (bank capped near 25°) instead of the full standard-rate bank angle.
Time / Speed / Distance Calculator
Classic E6B flight-planning relationship: Distance (nm) = Speed (kt) × Time (hr).
Weight & Balance Calculator
Generic worksheet — Moment = Weight × Arm; CG = Total Moment ÷ Total Weight. Enter only the stations that apply.
This is a generic calculation only — it does not know your aircraft's actual CG envelope or maximum gross weight. Always verify the result against the specific aircraft's POH/AFM weight and balance data.
Antenna Length Calculator
Calculate full, half, and quarter wavelength antenna dimensions from frequency.
0.95 for bare wire, 0.66 for solid polyethylene coax
HAM Radio Antenna Calculator
Calculate antenna element lengths for all amateur radio bands.
0.95 for bare wire, 0.66 for coax stub
Drone Flight Time Calculator
Estimate flight time based on battery capacity, cell count, and average current draw.
20% recommended to protect LiPo cells
Rocket Motor Calculator
Calculate total impulse, motor classification, and HPR certification level.
| Class | Impulse Range (N·s) | HPR Level |
|---|---|---|
| 1/4A | 0 – 0.3125 | None required |
| 1/2A | 0.3125 – 0.625 | None required |
| A | 0.625 – 1.25 | None required |
| B | 1.25 – 2.5 | None required |
| C | 2.5 – 5 | None required |
| D | 5 – 10 | None required |
| E | 10 – 20 | None required |
| F | 20 – 40 | None required |
| G | 40 – 80 | None required |
| H | 80 – 160 | None required |
| I | 160 – 320 | Level 1 |
| J | 320 – 640 | Level 1 |
| K | 640 – 1280 | Level 2 |
| L | 1280 – 2560 | Level 2 |
| M | 2560 – 5120 | Level 2 |
| N | 5120 – 10240 | Level 3 |
| O | 10240 – 20480 | Level 3 |
Battery Runtime Calculator
Calculate how long a battery will power a load based on capacity and draw.
Accounts for inverter and wiring losses