Depends on make and model of the firearm. In general, most .25 ACP pistols have a six or seven round magazine.
.45 ACP.
Most are in .380 ACP caliber. Sometimes called 9mm Short in Europe (or 9mm Corto or 9mm Kurz) What is marked on yours?
25 ACP
Many makers offer firearms that shoot the 380 ACP.
It was chambered in both 32 ACP and 380 ACP.
The Hi-Point Model JHP .45 ACP magazine typically holds 9 rounds of ammunition.
.45 ACP
.32 caliber. In a semi auto handgun, probably .32 ACP
0.380 ACP.
It is a .380 ACP caliber handgun produced by Colt Arms. It is a .380 ACP caliber handgun produced by Colt Arms.
As far as self defense handguns go, the .45 ACP is an extremely powerful and effective caliber, with a proven military track-record.
Technically, it would be .47 caliber, but I don't know of anything that is chambered in that caliber. .45 ACP is 11.43.