EU category check

Two questions decide almost everything about flying in the Open category: which subcategory the aircraft puts you in, and whether you have to register. They have different inputs, which is why people get one right and the other wrong. The subcategory follows the class mark, or the weight if there is no mark. Registration follows the weight or the camera, whichever triggers first.

What this calculator does

For the subcategory it applies the class mark, because once an aircraft carries one the mark is what binds. A C2-marked aircraft enables A2 regardless of what you weighed it at. Without a mark, weight alone decides: under 250 g behaves like A1, up to 25 kg like A3.

For registration it applies the three criteria in Article 14, of which the third is the one people miss: a camera or sensor able to capture personal data triggers registration even on a sub-250 g aircraft, unless the thing is classed as a toy. Most sub-250 g camera drones sold as "no registration needed" are not toys in that sense.

• Subcategory inputclass mark, or mass if unmarked
• Registration inputmass, or camera / sensor
• Open category ceiling25 kg

What it does not do

It does not model the 80 joule impact-energy criterion in Article 14, because you cannot look that figure up for your own aircraft and a calculator that asks for a number nobody has is theatre.

It does not tell you where you may fly. Geographic zones are set nationally and change, sometimes at short notice, and no static table can stand in for the current map. It also does not cover the Specific category, which is where you end up above 25 kg or outside the Open category's operational limits.

If you are still choosing an aircraft rather than checking one you own, the weight class is worth treating as a buying criterion in its own right: see choosing a camera drone. Building instead of buying puts the mass under your control, which the first build path covers.