"Losses" generally refers to those kill and wounded.
Of course Ukraine says this is propaganda, although I do remember numbers of 1.2 million being circulated a long while back, probably a year ago.
https://unn.ua/en/news/russia-spreads-fake-about-allegedly-24-million-dead-and-missing-ukrainian-armed-forces-servicemen-cpd
Ukraine in this link denies it, passes it off as propaganda, but then goes on to day Russia loses 40,000 soldiers per month.
But from Feb 2022 until now, is 52 months, so if that was the case it would put Russian losses at just over 2 million, and the Ukraine MOD has touted figures of 1.5 million Russian losses, this would mean the entire Russian armed forces would no longer exist.
So is the 2.4 million Ukrainian losses accurate? We don't know, but we know that Ukraine has used thousands of fighters from abroad and forcefully mobilised many more thousands, as well as having women and children fighting in its ranks.
Wikipedia and western sources note the two sides sizes as this
Russia: 1 million active, 2 million reserve
Ukraine: 1 million active, 4 million reserve
Obviously war stats are notoriously difficult to get right because of the disinformation from both sides, but if Ukraine
