Geneva - A total of 5,133,747 Ukrainians have fled the country since Russia invaded on February 24, the UN refugee agency said Friday.
The figure marks an increase of 48,387 from Thursday's data, UNHCR said.
Some 1,098,000 Ukrainians have left the country during April so far, compared with 3.4 million for the whole of March.
Women and children account for 90 per cent of those who fled abroad, with men aged 18 to 60 eligible for military call-up unable to leave.
The UN's International Organization for Migration (IOM) said an additional 218,000 citizens of third countries -- largely students and migrant workers -- have also escaped to neighbouring countries.
Beyond the refugees, the IOM estimates that 7.7 million people are displaced within Ukraine.
Before the invasion, Ukraine had a population of 37 million in the regions under government control, excluding Russia-annexed Crimea and the pro-Russian separatist-controlled regions in the east.
Meanwhile, 1.1 million Ukrainians have returned to their country since the war began.
Here is a breakdown of how many Ukrainian refugees have fled to neighbouring countries, according to UNHCR:
Poland - Nearly six out of 10 Ukrainian refugees -- 2,867,241 so far -- have crossed into Poland.
Many of them have travelled on to other states in Europe's Schengen open-borders zone.
Meanwhile, more than 800,000 people have crossed from Poland into Ukraine, Polish border guards said.
Before the war, Poland was home to around 1.5 million Ukrainians, chiefly migrant workers.
Romania - A total of 769,616 Ukrainians entered the EU member state, including a large number who crossed over from Moldova, wedged between Romania and Ukraine.
The vast majority are thought to have gone on to other countries.
Russia - Another 578,255 refugees have sought shelter in Russia.
In addition, 105,000 people crossed into Russia from the separatist-held pro-Russian regions of Donetsk and Lugansk in eastern Ukraine between February 18 and 23.
Hungary - A total of 480,974 Ukrainians have entered Hungary.
Moldova - The Moldovan border is the closest to the major port city of Odessa. A total of 430,170 Ukrainians had by Wednesday crossed into the non-EU state, one of the poorest in Europe. Most have moved on.
Slovakia - A total of 349,286 people crossed Ukraine's shortest border into Slovakia.
Belarus - Another 23,900 refugees have made it north to Russia's close ally Belarus.