FPV Tools
Build calculators from the FPV Guidebook app. Pick a tool, enter your numbers and read the result.
Motor KV
Find the right KV range for your build.
Recommendations are based on established FPV community references. Always check your specific motor and prop specs before flying.
Motor Limit
Work out the ESC or FC motor limit that caps a high-KV motor.
Set this value as the motor output limit in Betaflight, or as the motor limit in BLHeli. Results are approximate.
Thrust-to-Weight
Find out how your build performs.
TWR compares total motor thrust to the all-up weight of the drone with its LiPo. Above 2:1 is flyable, 4:1 is agile freestyle, and 5:1 or more is race or whoop territory. Enter per-motor thrust at your typical throttle (for example 50 to 75%).
Disc Loading
Propeller disc load and hover efficiency.
in
Disc loading is the all-up weight divided by the total propeller swept area. Lower values mean more efficient hover and longer flights. Higher values mean agile but power-hungry builds.
Motor Volume
Calculate and compare stator volume.
Stator volume = π × (diameter ÷ 2)² × height. More volume generally means more torque. Use it to compare motors alongside KV, prop size and battery voltage.
All five tools are in the FPV Guidebook app too. Next to 250+ illustrated parts, pinouts and a flying spots map.
