the_dunk_tank

From the NYT link:

The total number of Ukrainian and Russian troops killed or wounded since the war in Ukraine began 18 months ago is nearing 500,000

They break this down into Russian and Ukrainian figures like this:

Russia’s military casualties, the officials said, are approaching 300,000. The number includes as many as 120,000 deaths and 170,000 to 180,000 injured troops. The Russian numbers dwarf the Ukrainian figures, which the officials put at close to 70,000 killed and 100,000 to 120,000 wounded.

I don't put much stock in these numbers because they're estimations from a source motivated to paint an optimistic picture, but they come out to be about 300,000 and 190,000 casualties for Russia and Ukraine respectively.

The Mediazona source at least provides some information as to how they arrive at their count. It also states this:

The figures we provide are sourced from publicly available information, including social media posts from family members, local media coverage, and official statements from local authorities. However, these figures represent only a partial account and do not reflect the full extent of the casualties.

And later in the page in their methods section, this:

Our standard for confirmed deaths is stringent—it requires an official publication or social media post from a relative with corresponding details, accompanying photos or dates of burials from local messaging groups, or photos from cemeteries.

We exclude casualties sustained by units of the self-proclaimed DPR and LPR republics, and we do not rely on photographs of bodies (even with accompanying documents) published by Ukraine as these are difficult to verify.

So it's probably not a complete count of casualties. It's the best count we have of Russian casualties without being privy to Russia's internal tracking or using estimation. Unfortunately, without a comparable attempt to count Ukraine's casualties by similar methods, it's very hard to extrapolate from this to give a better picture of the balance of casualties on each side. I'd be very curious to see the same thing done for Ukraine, and if you or anyone knows of such a project, please do share.