Weight Determines Nearly Everything About What You Can Do
In the UK's drone regulatory framework, weight is the single most important variable. The maximum take-off mass (MTOM) of your drone determines which Open Category subcategory you fall under, what class marking applies, where you can fly in relation to people, and whether you can operate in certain environments at all. Under the retained EU Regulation 2019/947, the Open Category is divided into three subcategories โ A1, A2, and A3 โ with weight thresholds that govern which subcategory your drone qualifies for. A drone under 250g has different permissions from one between 250g and 900g, which in turn differs from one between 900g and 4kg, and so on up to the 25kg Open Category ceiling. The problem many operators face is that the relationship between weight, class marking, and operating permissions is not straightforward. A C0 class drone under 250g can fly in subcategory A1, but so can a C1 class drone under 900g โ with different proximity rules. Legacy drones without class markings have their own transitional provisions. The interaction of these variables creates confusion. Getting your weight category wrong means operating under the wrong rules. This could mean flying closer to people than permitted, operating in a subcategory that does not apply to your drone, or missing registration requirements entirely.
MmowW's Weight Category Calculator Gives You Certainty
The MmowW Drone Weight Category Calculator is a free tool that takes your drone's specifications and maps them to the correct weight category and operating subcategory under UK regulations. No interpretation required โ enter your details, receive your answer.
How It Works
Step 1: Enter your drone's maximum take-off mass. This includes the drone body, batteries, payload, camera, and any accessories that contribute to the total weight at takeoff. Step 2: Select your class marking. If your drone has a CE class marking (C0 through C4), select it. If it has no marking (legacy drone), the tool applies the appropriate transitional rules. Step 3: Review your category. The tool displays your Open Category subcategory (A1, A2, or A3), the operating restrictions that apply, and the maximum proximity to people permitted for your configuration. Step 4: Understand what changes if you add accessories. Adding a heavier camera, a spotlight, or a delivery payload changes the MTOM. The tool lets you test different configurations to see how weight changes affect your category.Key Benefits
Precision. Weight category boundaries are fixed in law. The tool maps your drone to the correct one without ambiguity. Awareness of proximity rules. Each subcategory and class marking carries specific rules about how close you can fly to uninvolved persons. The tool makes these explicit, so you know your limits before you fly. Legacy drone clarity. Drones without class markings have transitional provisions under UK law. The tool applies these correctly, so legacy drone operators understand their current position. Configuration flexibility. If you frequently swap payloads or accessories, the tool helps you understand how each configuration affects your weight category and what that means for your operating permissions.Real Scenarios Where Weight Clarity Matters
Scenario 1: The payload swapper. A surveyor uses the same drone with different cameras and sensors depending on the project. A lightweight RGB camera keeps the MTOM under 900g, qualifying for subcategory A2 with a C2 class marking. A heavier thermal imaging payload pushes the total above 4kg. The calculator shows that the heavier configuration moves the drone into subcategory A3, with different proximity rules. Scenario 2: The borderline hobbyist. A recreational pilot owns a drone that weighs 248g without a propeller guard but 260g with one. The two-gram difference changes whether the drone falls under the 250g threshold. The tool clarifies which configuration applies to which category. Scenario 3: The buyer doing pre-purchase research. Before purchasing a drone, an operator enters the manufacturer's stated MTOM into the tool to understand what operating restrictions will apply. She discovers that the drone she is considering falls into subcategory A3, which is more restrictive than she expected. She reconsiders and looks at a lighter alternative.FAQ
Q: What exactly counts towards maximum take-off mass?A: MTOM includes the drone airframe, batteries, propellers, camera, payload, and any other accessories installed at the time of takeoff. It is the total weight of everything that leaves the ground.
Q: My drone does not have a class marking. Can I still use the tool?A: Yes. Select "No class marking" or "Legacy drone." The tool applies the transitional provisions that cover drones without CE class markings under the UK regulatory framework.
Q: Does weight affect insurance requirements?A: Weight influences the risk profile of your operations, which in turn affects insurance considerations. Heavier drones generally carry higher risk. Use the MmowW Insurance Cost Estimator alongside this tool for a complete picture.
Try It Now โ Free, No Signup Required
Your drone's weight category determines the rules you fly under. The MmowW Weight Category Calculator gives you a definitive answer in seconds.
Check your weight category nowWhat's Next?
After confirming your weight category, check your registration obligations with the Registration Requirement Checker and test your regulatory knowledge with the Regulation Knowledge Quiz. MmowW makes compliance tools free because every operator deserves to fly with certainty. Loved for Safety. Ready for complete compliance management? Start your 14-day free trial โ ยฃ5.29/month, less than a coffee. Explore MmowW Drone SaaS