From what I see based on the numbers, Russia only has around 1.3 million troops (including reserves, and paramilitary, who already showed disloyalty to Putin). Ukraine has around a half million.

But Russian losses have been disproportionately greater, so they could run out of fighters sooner, if things keep up the way they've been. But considering that Ukraine is now getting more advanced weapons and support, Russia could lose more soldiers and high-value targets faster than before.

When you factor in that Russian soldiers have almost no motivation to fight, while Ukrainians have every reason to defend their home, things don't look good for Russia.

What can tip the balance is whether other countries decide to support Russia, then the world would be in trouble.