This report analyses the effect of the Russian Invasion on the longer-term future of Ukraine’s population size and structure. The qualitative scenarios spanning a range of possible migration futures are translated into quantitative population projections using a multistate population model which shows the evolution of the size and age-sex composition of Ukraine’s population up to 2052. Under the most pessimistic scenario of Long war, low return scenario we project a decline of 30% of the population. The difference of in population decline across the four considered migration scenarios matches the uncertainty in the UN projections suggesting that migration will be similarly important as fertility and mortality in driving population change in Ukraine following the war.