06/11/2016 6:14 AM AEDT | Updated 06/11/2016 6:27 AM AEDT

Now You Can Calculate The Greenhouse Cost Of Your Dinner

You probably won't want a steak sandwich.

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Steak sandwiches are expensive for the planet.

No restaurants ask you to carbon offset your dinner, but there's a new guide to determine your meal's greenhouse gas emissions.

Researchers from RMIT University collaborated with Lancaster University to come up with a comprehensive list of common foods and their corresponding greenhouse gas emissions needed to grow and process it.

Researchers found grains, fruit and vegetables had the lowest impact, then nuts and pulses.

As for protein, eggs, chicken, pork and most fish had a medium impact while beef and lamb had the highest impact.

On average, 1kg of greenhouse gas emissions is equal to:

50 onions

20 apples

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Producing 20 apples produces as much greenhouse gas as 800ml of milk.

2.6kg oats

1kg lentils

1.2kg of peanuts

800ml of milk

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Salmon produces about half the greenhouse gas as pork.

290g of salmon

five small eggs

270g of chicken

244g of kangaroo

212g of rabbit

131g of Australian pork

Beef and lamb don't get much bang for your buck of gas emissions.

57g of Australian lamb

44g of Australian beef

Researcher Stephen Clune said beef and lamb did not score well because they were ruminant animals with multiple guts.

"You would have a hard time arguing that you can replace beef with onions as they serve very different culinary and dietary requirements," Clune said in a statement.

"However, it is possible to substitute red meat with other meats, or plant-based protein sources such as lentils and nuts that have a lower impact.

"Our results could be used with confidence to plan menus for individuals and catering companies who want to reduce their carbon footprint, by selecting foods from different categories."