An airline in Finland has announced it will begin weighing passengers with their carry-on luggage to better estimate the plane's weight before take-off.

The controversial move comes from Finnish carrier Finnair, who told media they began 'measuring' passengers departing from Helsinki on Monday, February 5.

'So far, more than 500 volunteer customers have participated in the weigh-ins,' spokeswoman Kaisa Tikkanen said.

Finnair, which services the UK with budget flights to and from Finland, noted in a statement airlines work out the weight of the plane, its interior, and passengers on board to balance the flight and make for safe transit.

Airlines may use average weights provided by aviation authorities - assumed to be 88kg - or collect their own data, it said.

Finnair assured potential passengers that collected data is not linked 'in any way' to customers' personal data in their statement.

'Only the customer service agent working at the measuring point can see the total weight, so you can participate in the study with peace of mind,' said Satu Munnukka, head of ground processes at Finnair.