An estimated 41 million seats worldwide have been scrapped due to the global grounding of the Boeing Max 737.
Air travel data firm OAG compared the numbers from mid-February before the grounding to early August to calculate the reduction in seat capacity.
OAG executive vice-president John Grant said: "For every carrier there appears to be a significant reduction in capacity offered, much of which would have been assumed in the original planning of the carriers for this financial year."
About 11 million seats have been dropped in North America, with Southwest Airlines, Air Canada, United and American Airlines all significantly impacted.
"Accountants will, of course, be keeping a very close eye on every expense incurred as a result of the grounding as they prepare a series of claims for the inconvenience caused," OAG said.
Airlines’ loss of revenue as a direct result is likely to exceed $4 billion up to November, and even higher if the jet has not been cleared to fly again by then.
"Many carriers have of course made operational adjustments, continued to operate aircraft with perhaps lower levels of capacity and incurred significant additional cost," Grant added in the report.
