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 its species, age, health, and surroundings. A tree produces a different amount of oxygen in summer compared to winter. So, there is no 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."

"A single mature tree can absorb carbon dioxide at a rate of 48 pounds per year and release enough oxygen back into the atmosphere to support two human beings."​

"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."​

"A 100-foot tree, 18 inches diameter at its base, produces 6,000 pounds of oxygen."

"On average, one tree produces nearly 260 pounds of oxygen each year. Two mature trees can provide enough oxygen for a family of four."

"Mean net annual oxygen production (after accounting for decomposition) per hectare of trees (100% tree canopy) offsets oxygen consumption of 19 people per year (8 people per acre of tree cover), but ranges from nine people per hectare of canopy cover (4 people/ac cover) in Minneapolis, Minnesota, to 28 people/ha cover (12 people/ac cover) in Calgary, Alberta."

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. However, trees perform photosynthesis during daylight hours. At night, they use oxygen and release carbon dioxide.

Sources