I don't know how reliable RFE is as a source of news and analysis but here is a link and the first couple paragraphs of a recent (March 17) article on the war.
"According to conservative estimates, Russia has lost more troops in three weeks of war in Ukraine than the United States did in more than 20 years in Afghanistan and Iraq combined.
U.S. and British defense officials say more than 7,000 Russian soldiers have been killed so far. The figure is considered on the low end of the casualty count, with the Ukrainian Defense Ministry saying its forces have killed more than 14,000. Moscow has only issued an official casualty number once, on March 2, when it said 498 soldiers had been killed. The Russian Defense Ministry has not issued an estimate since."...