Tools
Calculators
Four calculators for the decisions that are cheaper to get right before you order than after. Each one shows its formula.
All four
- T-03
EU category check
Which subcategory of the Open category an aircraft falls into, from its mass and class mark, and what that permits.
- T-01
Thrust to weight
Total static thrust against all-up weight, and what the resulting ratio feels like to fly.
- T-02
Flight time estimate
Pack capacity against average current draw, with an explicit reserve.
- T-04
Prop clearance
Whether a prop size clears the arms and the camera on a given frame geometry.
What these calculators are for
Every calculator here states its formula and its assumptions on the page, and shows the working rather than only the answer. That is the point of them: a number you cannot check is a number you cannot argue with, and build decisions are arguments.
Where a result depends on something we cannot know, the calculator says so instead of substituting a default and hoping. Static thrust figures from a manufacturer are measured on a test stand at full throttle with a specific prop and a specific cell count, and your build is none of those things.
What they are not
None of these replace the authority that actually decides. The EU category check reproduces the logic of Regulation (EU) 2019/947 as we read it, but the binding source is the regulation itself and your national aviation authority, both cited on the page.
They are also not a substitute for testing. We have not bench-tested any component on this site, and no calculator here is fed by measurements we took.