UNHCR, the UN refugee agency, said 4,796,245 million Ukrainians had left the country since February 24.
The UN's International Organization for Migration (IOM) says nearly 215,000 third-country nationals have also escaped to neighbouring countries.
Friday's figures from the UNHCR were up 59,774 on those issued Thursday.
More than 2.7 million Ukrainian refugees -- nearly six in 10 who have left since the war began -- have fled to Poland. More than 725,000 reached Romania.
UNHCR figures show nearly 645,000 Ukrainians fled in February, with nearly 3.4 million doing so in March and more than 760,000 leaving so far this month.
Women and children account for 90 percent of those who escaped, with men aged 18 to 60 eligible for military call-up and unable to leave.
Nearly two-thirds of all Ukrainian children have been forced from their homes, including those still inside the country.
The nearly 215,000 third-country nationals who have fled -- people who are citizens of neither Ukraine nor the country they entered -- are largely students and migrant workers.
Beyond the refugees, the IOM estimates 7.1 million people have left their homes but are still in 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.
Here is a breakdown of how many Ukrainian refugees have fled to neighbouring countries, according to UNHCR:
Nearly six out of 10 Ukrainian refugees -- 2,720,622 so far -- have crossed into Poland, according to the UN.
Many people who go to Ukraine's immediate western neighbours travel on to other states in Europe's Schengen open-borders zone.
The World Health Organization said Poland had made 7,000 hospital beds available for the sick and wounded from Ukraine, of which 20 percent were currently in use.
Some 652,000 people have crossed from Poland into Ukraine since the war began.
Before the crisis, Poland was already home to around 1.5 million Ukrainians, chiefly migrant workers.
A total of 726,857 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.
Another 484,725 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.
A total of 447,053 Ukrainians have entered Hungary.
The Moldovan border is the closest to the major port city of Odessa. A total of 419,499 Ukrainians have crossed into the non-EU state, one of the poorest in Europe.
Most of those who have entered the former Soviet republic of 2.6 million people have moved on but an estimated 100,000 remain, including 50,000 children -- of whom only 1,800 are enrolled in schools.
"Refugee children from Ukraine have fled a brutal war and have arrived dispossessed and traumatised in Moldova. They are very vulnerable and need immediate support," said Yasmine Sherif, Director of Education Cannot Wait.
"Public schools are open to refugee children; however, the capacity is over-stretched and there is a need for urgent mental health and psycho-social services, sanitation, and teachers."
A total of 329,597 people crossed Ukraine's shortest border into Slovakia.
Another 22,827 refugees have made it north to Russia's close ally Belarus.