Introducing Our Drone Build Calculator

Our drone build calculator is a free tool that tells you what a DIY drone can lift and how long it will fly — before you buy a single part. Pick a motor, a propeller, and a battery, set your payload and altitude, and it returns the whole flight envelope: thrust-to-weight, hover throttle, top speed, flight time, and payload margin. You can open the calculator here.

It started from a real frustration. For a DIY drone, it's almost impossible to know in advance what you can lift — and that one question decides everything else about the build.

If you're building your own drone, the hardest question comes first: how big does it need to be? A first-time builder has no way to know whether a 7-inch frame will lift their camera, or whether they need to jump to a 10-inch — and what that costs them in flight time. The real numbers are buried in forums or learned through expensive trial and error.

The questions pile up fast. Do I need a 7-inch or a 10-inch? What's the trade-off? How big does a drone have to be to lift 5 kg, or to carry a LiDAR sensor? How do I get longer flight times? Outside of FPV racing and freestyle, almost nobody had published this in a usable form, and the ready-made answer was a $5,000-plus commercial drone. We wanted machines we own, control, maintain, and repair ourselves — which meant we needed the maths first.

The Build Calculator turns three component choices into a full flight envelope. Select from common motor, propeller, and battery configurations — or enter exact specs for anything — set the payload and altitude, and read off thrust-to-weight, hover throttle, top speed, flight time, and payload margin.

The numbers are corrected for real-world conditions, not just spec sheets — in our case, typical Mindanao field conditions — so what you see is closer to what you'll actually fly. It's honest about its limits, too: predictions land within about ±15% of measured flight data, which is fine for narrowing design choices but not for safety-critical margins. A reading of 2.1 thrust-to-weight really means somewhere around 1.9 to 2.3 in practice. Open the calculator.

The Build Comparison tool puts several builds next to each other so the trade-offs are obvious. Add multiple configurations — from presets, component selection, or raw specs — and compare them in a table, with the best and worst value in each metric highlighted. Drag the columns to reorder them. This is where the 7-inch-or-10-inch question gets settled: line the two builds up and see exactly what the bigger frame buys you and what it costs. Open comparison.

Build Recommendations works backwards from the question that matters most: what do I need to lift this? Enter a target payload weight and your operating conditions, and the tool searches every compatible motor, propeller, and battery combination and returns a ranked list — optimised for flight time, efficiency, and cost.

So if you need to carry a 1.5 kg LiDAR sensor over a plantation, you don't guess at a frame and hope. You enter the weight and get builds that can carry it with margin to spare. Open recommendations.

We built these tools because the alternative didn't fit us. A $5,000 commercial platform is a closed box: you don't own the design, you can't repair it in the field, and you can't teach someone to build the next one. For agricultural surveying in the Philippines, we wanted drones we control end to end — sized, built, maintained, and fixed by the people who fly them.

That's the same reason we publish the rest of our material openly, from the agricultural drones guide to LiDAR for canopy health. And once a build is sized, you can practise flying it in our free drone simulator before you ever solder a wire.

Stop guessing at parts. Enter your payload, or pick your components, and see the real flight envelope in seconds — free, in your browser. Open the build calculator.

What does the drone build calculator do?

It estimates a DIY drone's flight envelope — thrust-to-weight, hover throttle, top speed, flight time, and payload margin — from your motor, propeller, and battery choice, corrected for real-world conditions.

Do I need to know my parts already?

No. Build Recommendations works the other way: enter a target payload and it finds compatible motor, propeller, and battery combinations for you.

7-inch or 10-inch — which do I need?

Put both builds into the comparison tool with your payload and conditions, and read off the flight time and margin each one gives. That's exactly the question it's built to answer.

Can it size a drone for a LiDAR sensor?

Yes. Enter the sensor's weight as the payload and it returns builds that can lift it with margin to spare.

How accurate is it?

Predictions land within about ±15% of measured flight data — good for narrowing design choices, not for safety-critical margins. Verify a shortlisted build with a brief test flight.

Is it free?

Yes — free, in your browser, with no sign-up.

The information to size a DIY drone always existed — it was just scattered across forums, locked inside racing communities, or priced into a $5,000 commercial platform. We pulled it into one free tool so a first-time builder can answer 'what do I need to lift this?' before spending a peso on parts.

For what these drones do once they're built, see our guide to agricultural drones in the Philippines and starting a drone services business.

Lumipad Drones is a non-profit that trains rural Filipinos to build, fly, and maintain low-cost agricultural drones, and to launch the microenterprises that serve local farmers. To learn more about our work, see our about page, or apply to join a program. You can also try our free drone flight simulator — built for agriculture and the Philippines, and runnable right in your browser.