How Much Oxygen Does One Tree Produce?

Oxygen Produced by Photosynthesis

Trees oxygen
Even a single tree can produce enough oxygen to support several people. Yasuhide Fumoto / Getty Images

You've probably heard that trees produce oxygen, but have you ever wondered just how much oxygen one tree makes? The amount of oxygen produced by a tree depends on several factors, including the species of tree, its age, its health, and the tree's surroundings. A tree produces a different amount of oxygen in summer compared to winter. So, there is no one definitive value. Here are some typical calculations.

"A mature leafy tree produces as much oxygen in a season as 10 people inhale in a year."
Arbor Day Foundation

"A single mature tree can absorb carbon dioxide at a rate of 48 lbs/year and release enough oxygen back into the atmosphere to support 2 human beings."​
- McAliney, Mike. Arguments for Land Conservation: Documentation and Information Sources for Land Resources Protection, Trust for Public Land, Sacramento, CA, December 1993

"One acre of trees annually consumes the amount of carbon dioxide equivalent to that produced by driving an average car for 26,000 miles. That same acre of trees also produces enough oxygen for 18 people to breathe for a year."​
- New York Times

" A 100-ft tree, 18" diameter at its base, produces 6,000 pounds of oxygen."
- Northwest Territories Forest Management

"On average, one tree produces nearly 260 pounds of oxygen each year. Two mature trees can provide enough oxygen for a family of four."
- Environment Canada, Canada's national environmental agency

"Mean net annual oxygen production (after accounting for decomposition) per hectare of trees (100% tree canopy) offsets oxygen consumption of 19 people per year (eight people per acre of tree cover), but ranges from nine people per hectare of canopy cover (four people/ac cover) in Minneapolis, Minnesota, to 28 people/ha cover (12 people/ac cover) in Calgary, Alberta."
- U.S. Forest Service and International Society of Arboriculture joint publication

Notes About Numbers

Note there are three ways to look at the amount of oxygen produced:

  • One type of calculation simply looks at the average amount of oxygen produced via photosynthesis.
  • A second calculation looks at net oxygen production, which is the amount made during photosynthesis minus the amount the tree uses.
  • A third calculation compares the net oxygen production in terms of gas available for humans to breathe.

It's also important to remember that trees not only release oxygen, but also consume carbon dioxide.