The dead are part of 1.5 million Russian casualties in Ukraine, Air Chief Marshall Sir Richard Knighton, head of the UK's defence staff, said.
The UK figures roughly coincide with those published by the Ukrainian military. There was no immediate comment from Russian officials.
Moscow's bigger army is struggling to make headway on the battlefield, with western officials and analysts saying the Russian advance has slowed significantly this year.
Russia's armed forces have also lost an "enormous" amount of military material, Knighton told reporters: including more than 10,000 armoured and protected vehicles, close to 3000 air defence and artillery systems, and in excess of 370 aircraft and helicopters.
He did not quantify Ukraine's losses and neither Moscow nor Kyiv give regular updates on battlefield losses.
Russian drones targeted roadside petrol stations in Kyiv for a second straight day on Friday, as Moscow broadened its air war in what Ukrainian officials say is an effort to rattle civilians.
The attacks struck two Ukrnafta facilities, killing two people and wounding six at one of them, the prosecutor's office said.
Russian strikes on urban gas stations have intensified in recent months, mostly in regions near the front line in eastern and southern Ukraine.
"Russia is systematically attacking places where it knows people will be spending their time going about their daily lives, seeking to maximise casualties, spread fear, and put pressure on Ukrainian society," Foreign Minister Andrii Sybiha said on X.
Pavlohrad, a city in central Ukraine, observed an official day of mourning on Friday for five residents killed near shopping malls by Russian drones the previous day.
In the southern city of Zaporizhzhia, a 32-year-old woman and her 10-year-old son were wounded in an overnight Russian drone attack, Ukraine's State Emergency Service said. The drones struck a nine-storey apartment block and a shopping mall, it said.
Ukraine, meanwhile, has extended its long-range drone campaign in Russia, straining air defences across its bigger neighbour's vast territory.
On Thursday, its military reported hitting a refinery more than 3000km away in Siberia as Kyiv tries to hurt Russia's vital oil sector. Its strikes have caused fuel shortages in Russia, one of the world's biggest energy producers.
Russia's oil product exports hit record lows in August, and Moscow is importing fuel from South Korea and India, the Centre for Research on Energy and Clean Air said.
Ukraine launched a major barrage overnight from Thursday to Friday, with the Russian Defence Ministry saying 777 drones were intercepted over 16 Russian regions, as well as occupied Crimea and the waters of the Azov and the Caspian seas.
Two people were killed and three others wounded in a Ukrainian drone attack on the Tula region south of Moscow, local officials said.
Ukrainian President Volodymyr Zelenskiy said long-range strikes hit eight Russian regions, including a business and an oil facility in the Saratov region.
The attacks were "aimed at reducing Russia's capacity to wage war", he said on X.
Indian Prime Minister Narendra Modi on Friday urged Russian President Vladimir Putin to enter negotiations to end the war as the two leaders met in New Delhi ahead of the BRICS summit.
Dialogue and diplomacy are the right way to resolve conflicts, Modi told Putin, according to a statement from the Indian Foreign Ministry.
- with Reuters
8°C