By using data gathered of the passengers’ weight, an airline can work out the exact amount of fuel it needs to each journey.
Fuel needs for planes can vary considerably depending on the total weight being carried.
The heavier the load, the more fuel is needed and the higher the carbon emissions.
Currently, airlines estimate using an inexact science based on the gender ratio of the passengers on board.
Many allow 88kg (13.8 stone) for men, 70kg (11 stone) for women and 35kg (5.5 stone) for children.
But this method means airlines often use more fuel than they need to, according to Fuel Matrix, the company behind the proposed weighing system.
Chief operating officer Nick Brasier told The Independent that as much as one per cent more fuel is added for most flights than is needed.
They then burn between 0.3 and 0.5 per cent more fuel due to the extra weight of the fuel.
With exact weights, total savings on fuel could be as much as £750million worldwide, the company claims.
Talks are currently underway between the Berkshire-based firm and several long-haul airlines in the UK over implementing the system.
The weighing would be done through discreet “pressure pads”, and could take place while passengers check in or when they leave their luggage at self-service bag drops.
Or it could happen as they pass through security scanners.
Explaining his concept, Mr Brasier said: “We’re not suggesting people should stand on the scales, but airports could fit ‘pressure pads’ in the bag-drop area in front of each screen.
“After the bag has been checked in, the system can ask, ‘Are you standing on the pressure pad?’
“If the passenger taps ‘Yes’, then the weight can be recorded and passed confidentially to the airline.”
Nick added to Sun Online Travel: “Our patented technologies are relevant to both airports and airlines in reducing fuel burn, CO2 emissions and carbon footprints.
“Our discussions in the sector continue to progress well, and we’ll be pleased to provide a more detailed update in the coming months.”