... guess based on the Cougar Club Donor Report released a few years ago with the 2019-20 revenues/expenses percentages.  They reported that 6% of the total revenue for BYU athletics that year was from a "spendable endowment"  figure.  That year BYU reported $76M in total Revenues to EADA and so that works out to just under $5 Million as a spendable endowment figure.  I think I've heard it said that 4-5% is a pretty common and conservative figure of what endowments usually spend per year.  So would it be reasonable to assume that BYU's dedicated Athletic Endowment is at around $100M in 2020 and likely higher now?  Anyone know if that's close to reality? 

If it is $100M, that would put BYU at 14th among all FBS Public universities (pasted in the full list of 2022-23 Athletics Dedicated Endowments from Sportico's Database below), though I'm sure Stanford and Notre Dame and Duke and a few other Private schools have larger ones... 

I know the total school endowment for BYU is closing in on $3Billion (#67 on this list of all endowments worldwide... #1 is Ensign Peak Advisors FYI)

Athletics Dedicated Endowments 2022-23 (all public schools):

Total:  $4,377,633,334 
North Carolina $483,670,889
California $298,178,247
Virginia $238,667,913
Penn State $221,178,611
Michigan $219,307,662
Kansas $207,217,505
Georgia Tech $186,608,103
Ohio State $136,797,120
Wisconsin $135,408,044
Georgia $128,852,489 (2021-22 figure added in by me.. they didn't fill in this value for 2022-23 report)
Washington $115,483,313
Michigan State $107,710,838
Alabama $103,947,009
Indiana $89,729,003
Florida State $82,809,639
Iowa $80,042,925
Florida $75,209,702
Virginia Tech $72,843,420
UCLA $72,436,410
Illinois $70,583,246
Texas $67,164,805
Oregon $62,173,451
West Virginia $61,415,002
Rutgers $59,384,971
Tennessee $59,021,021
Connecticut $57,224,692
Purdue $54,348,057
Minnesota $51,469,732
Oklahoma $47,546,867
Nebraska $44,302,936
Average $44,218,518
NC State $42,566,033
Missouri $41,628,376
Old Dominion $37,727,193
Colorado $34,758,710
LSU $33,607,415
Texas Tech $32,099,589
Miami (Ohio) $28,728,173
Kentucky $26,291,440
Maryland $26,267,191
East Carolina $24,905,949
Washington State $24,638,355
Arizona State $24,325,500
Kansas State $22,350,674
UNLV $22,340,332
Charlotte $21,479,730
Arizona $21,256,355
Oregon State $19,911,134
Western Michigan $19,370,641
Cincinnati $18,343,786
Bowling Green $18,220,405
Arkansas $16,778,048
UTEP $15,181,484
San Diego State $14,897,760
Auburn $13,600,424
Nevada $13,226,030
App State $11,719,652
Marshall $11,540,539
Iowa State $10,448,178
South Florida $10,364,110
Texas State $9,744,792
Utah $9,532,599
Houston $9,424,267
Utah State $8,100,307
Southern Mississippi $8,043,473
Fresno State $7,745,924
Ohio $7,474,486
South Carolina $7,411,219
New Mexico $7,101,497
San Jose State $6,861,416
Wyoming $6,346,444
Buffalo $6,305,011
Akron $5,127,469
Colorado State $5,122,874
Ole Miss $4,794,772
Eastern Michigan $4,287,668
Louisiana, Lafayette $3,770,501
Mississippi State $3,673,660
Louisville $3,537,000
Memphis $3,339,103
Middle Tennessee $3,176,392
Georgia Southern $2,995,826
New Mexico State $2,877,555
North Texas $2,102,169
Arkansas State $1,921,916
Louisiana Tech $1,848,693
UCF $1,782,098
South Alabama $1,747,029
Northern Illinois $1,720,256
Georgia State $1,715,063
Central Michigan $1,659,934
Texas A&M $1,230,562
UTSA $1,210,348
FIU $921,311
UAB $868,355
FAU $766,654
Louisiana, Monroe $711,880
Clemson $178,472
Air Force $0
Coastal Carolina $0
Western Kentucky $0

The following schools didn't fill in this value in their 2022-23 report
Troy
Toledo
Oklahoma State
Navy
Massachusetts
Kent State
James Madison
Hawaii
Georgia
Boise State
Ball State