PDJT beats them all...$10.9 trillion (and counting {up}):
PDJT: $10.91 Trillion (so far)
Obama: $9.32 Trillion
Biden: $8.45 Trillion
G.W. Bush: $4.90 Trillion
Reagan: $1.86 Trillion
Clinton: $1.54 Trillion
H.W. Bush: $1.33 Trillion
Carter: $0.30 Trillion
The rest are not even close.
https://www.us-debt-clock.com/presidents
You have to adjust dollars to inflation.
$1 Trillion during Reagan is not same as $1 Trillion during Trump.
Even better comparison is PERCENTAGE increase by each president to national debt. Of course, spending bills are NOT initiated by POTUS but he signs the spending bills to make them law. POTUS can always veto any bill, and then congress needs more votes to override the veto.