It is already distressing to find out that your checked luggage is overweight. Now, Finnish carrier Finnair wants to know how much you and your carry-on bags weigh.

There is no need to panic, though: the weigh-in is voluntary.

But it will help the airline better estimate the weight of a plane’s load to ensure safe operation of flight, Finnair said on Feb 5.

The trial is being conducted in February, April and May 2024 on flights departing from Helsinki Airport in Finland.

The procedure will also be anonymous, the airline said in a statement.

“We use the weighing data for the average calculations required for the safe operation of flights, and the collected data is not linked in any way to the customer’s personal data,” said Finnair’s head of ground processes Satu Munnukka.

The weigh-in will rotate between short Schengen-area flights and longer-haul ones, NBC News reported. The Schengen area is a border-free travel zone comprising 27 European countries.

A CNN report said Finnair is collecting the data for both the winter and summer seasons. This is because passengers tend to wear heavier clothing in winter.

The data for February will feed into the winter readings, while April and May will provide information for summer.

The trial started on Feb 5 and by Feb 8, at least 800 people had taken part, according to CNN.

The airline said it was “positively surprised by the number of volunteers”.

Those who took part in the trial were gifted with a baggage tag, the Guardian reported.

A plane’s maximum weight includes checked baggage and cargo, fuel, onboard catering and the total number of people onboard.

Airlines usually know the weight of these aspects except that of passengers and their carry-on bags, which is “calculated using average weights confirmed by the Civil Aviation Authority”, said Finnair.

“The alternative option is for airlines to either use their own measurements and confirmation of their results by the authority, or use standard weights defined by the European Aviation Safety Authority.”

Finnair has been using its own measurements since 2018, but these need to be updated every five years due to regulatory requirements.

The airline is not an exception in its move to collect weight data.

Between Jan 22 and Jan 31, South Korea’s Asiana Airlines weighed some passengers travelling out of Gimpo International Airport in Seoul for similar reasons.

In late May 2023, Air New Zealand did the same for certain flights departing from Auckland International Airport.