Ukraine: 603,628 km² (233,062 sq mi) — 2nd largest country entirely in Europe (after Russia).
Belarus: 207,600 km² (80,155 sq mi) — 84th globally, 13th in Europe.
Ukraine's vast territory encompasses the entire Dnieper basin, the Carpathian foothills, the Crimean Peninsula, and the Black Sea coast. Belarus is landlocked, centered on the upper Dnieper and Neman basins, with a more compact, rectangular shape. Historically, the Grand Duchy of Lithuania (which included Belarusian lands) expanded eastward into Ruthenian (Ukrainian) territories, but the modern borders reflect Soviet-era administrative divisions (1922–1991) and post-WWII settlements.
Ukraine: ~37M (pre-2022) / ~28M (2024 est., war-affected). Belarus: ~9.2M. Ukraine's population density is higher (61/km² vs 46/km²), reflecting its more fertile steppe and industrial east.