They actually do weigh humans, just as an average, not per person. Every flight's weight and balance uses a set passenger-plus-carry-on figure:
- In Europe, EASA's standard is 84 kg per adult including carry-on. Its 2022 survey of 4,164 volunteers at six airports found 76.3 kg body + 7.7 kg bag, so the number stayed.
- Airlines can measure their own instead. Finnair had volunteers step on a scale with their bags at Helsinki in 2024 (anonymous, only the total recorded) and uses those averages 2025 to 2030 after Traficom approves them.
- In the US, FAA Advisory Circular 120-27F (2019) stopped publishing fixed averages; airlines use CDC health-survey weights or their own surveys.
So your 50 kg person is already priced into the average. The carry-on limit is partly about bin space and partly fees, but it's not the only weight they count. Sources: finnair.com (29 Apr 2024), easa.europa.eu 2022 standard passenger weights review, FAA AC 120-27F.
