← Calculators
The Toolbox — Calculators
Avionics, Aerospace & Flight
Antenna length, HAM antenna, drone flight time, rocket motor classification, and battery runtime calculators.
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.
15 A (preset for Mini Quad (3"))
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