Planning a custom drone build starts with choosing the right combination of motors, propellers, and batteries. This free calculator lets you select real components from a database of tested parts and instantly see the performance estimates that matter: thrust-to-weight ratio, hover throttle, estimated flight time, top speed, and payload capacity.
The payload margin tells you how much extra weight your drone can carry beyond its own components — cameras, sensors, cargo, or agricultural spray equipment. Select your frame size, motor, propeller, and battery, then check the payload margin in the results panel. For agricultural or delivery drones, aim for a thrust-to-weight ratio of at least 2.5:1 to maintain stable flight under payload.
Flight time depends on your battery capacity, the power each motor draws at hover, and the total weight of the build. The calculator estimates hover throttle percentage and power consumption, then divides your battery's energy by the hover power draw to give you an estimated flight time. Real-world flight time is typically 70-80% of the calculated value due to maneuvering, wind, and non-hover flight.
Not sure which motor or battery is the better choice? The build comparison tool lets you calculate two or more configurations and see exactly how they differ on every metric — flight time, thrust, weight, and payload margin. This is the fastest way to answer questions like "is the 2807 1500KV worth the extra weight over the 2806.5 1300KV?"
If you're starting from a payload requirement rather than a component list, the recommendations tool works in reverse. Enter your target payload weight and it suggests the best motor, propeller, and battery configurations from the database that can carry it with safe thrust margins.
Air density decreases at higher altitudes and temperatures, reducing propeller thrust. The calculator adjusts its estimates based on your operating conditions so you can plan builds for highland agricultural areas or tropical climates where thinner air means less lift per motor.
This tool is completely free — no download, no account, no ads. It runs entirely in your browser and is built by Lumipad Drones, a non-profit drone training program that trains rural Filipinos to build and fly agricultural drones. All of our tools are open source and designed to work on low-bandwidth connections and older devices.
Ready to practice flying? Try our free browser-based drone simulator — no download required.