I haven’t done any technical calculations. On a quick glance I’d say all of this parking is about half the size of the park itself. Very little parking inside the main park boundaries, which is mostly for service vehicles (these spaces aren’t highlighted).
Just something I was curious about, it’s wild how much we accommodate, and how much space we waste, for cars.
Edit: not shown is the large lot southeast of the park. It is about three times the size of the lot to the southwest. There are other lots further outside the picture that add additional parking space not shown. Thanks to RvTV95XBeo for pointing this out.
You’re missing 2 more lots!
On the opposite side of the Harbor and Ball Rd. intersection there’s another parking lot. This is “Ball Lot” and is used by employees. Employees need a shuttle to get to work.
Further down Katella, across the street from the convention center, there’s Toy Story/“K Lot”, which is a combination parking lot for guests and more employee parking. This is the largest parking lot of them all, taking up an entire city block.
The lot you’ve marked across from House of Blues is indeed a Disney lot but it is rarely used. Additionally, the “lot” you’ve marked inside California Adventure isn’t a “real” parking lot - just a place for storage of maintenance trucks and stuff that rarely leaves the bounds of the park. If you’re counting those, there’s a lot more area you should count (all of the outside of Indiana Jones/Haunted Mansion, everything from the backside of Space Mountain to Main Street). There’s also a parking garage just below the spot you’ve marked in Team Disney Anaheim - that gray structure to the south of the parking lot is a parking garage for corporate folks that have their office behind the park.
(I used to work at Disneyland.)