Institute for the Study of War: some 280,000 Russian casualties from January through September, according to leaked Russian estimate

The Kremlin continues its reflective control campaign aimed at preventing the US from selling Tomahawk missiles to Ukraine. Kremlin Spokesperson Dmitry Peskov stated on October 7 that the US sending Tomahawk missiles to Ukraine would be a “serious escalation” that would not change the situation on the frontline in Ukraine and noted that Tomahawk missiles can carry a nuclear warhead.[1] Peskov stated that Putin made his position “unequivocally” clear on how Russia would respond to such action, referring to Putin’s October 2 and 5 threats against the US provision of Tomahawk missiles. Putin threateningly warned the United States against selling Tomahawk missiles to Ukraine on October 2, claiming that American military personnel would have to directly participate in Ukrainian Tomahawk strikes.[2] Putin later threatened on October 5 that US provisions of Tomahawk missiles would “lead to the destruction” of the “emerging positive trend” in US-Russian relations. ISW continues to assess that the Kremlin is attempting to portray potential US Tomahawk deliveries to Ukraine as a dangerous escalation to deter the United States from sending such weapons to Ukraine.

Leaked Russian estimates of Russian killed in action (KIA) to wounded in action (WIA) rates in Ukraine underscore the impact of increased tactical drone usage in Ukraine and the extent to which drones complicate ground advances and casualty evacuation. Ukraine’s “I Want to Live” initiative published leaked Russian data on October 6 detailing Russian military casualties from January to August 2025.[9] The data indicates that Russian forces suffered a total of 281,550 casualties of which: 86,744 were killed in action (KIA), including 1,583 officers and 8,633 penal recruits; 33,996 are missing in action (MIA), including 11,427 penal recruits; 158,529 were wounded in action (WIA), including 6,356 officers and 16,489 penal recruits; and 2,311 were captured. Ukraine’s “I Want to Live” initiative’s data on total Russian military casualties from January to August 2025 is similar to Ukrainian Commander-in-Chief General Oleksandr Syrskyi’s report that Russian forces had suffered 299,210 casualties since January 2025 as of September 9.[10] Ukraine’s “I Want to Live” initiative reported that Russia’s casualty ratio is one KIA for every 1.3 WIA, likely due to insufficient tactical medicine training and the Russian military command’s frequent failure to sufficiently rehabilitate WIA. The standard KIA to WIA ratio is one-to-three, which demonstrates that the Russian forces currently appear to have an abnormally high KIA to WIA ratio (1:1.3) likely due to the efficacy of pervasive tactical-level drone strikes that have created kill zones (an area immediately near the frontline where a mass of tactical strike and reconnaissance drones pose an elevated risk to any equipment or personnel that enters the area) throughout the theater, complicating both sides ability to evacuate casualties and triage WIA.[11] ISW has previously observed reports that the Russian military command is struggling to and frequently refusing to recover WIA, likely due to the threat of Ukrainian drone strikes that are significantly complicating movement on the battlefield.[12]

The leaked estimates indicate that Russian forces suffered their highest casualties in the Pokrovsk, Kupyansk, and Lyman directions between January and August 2025, reflecting command prioritization of these sectors of the front. The “I Want to Live” documents indicate that the Russian Central Grouping of Forces, responsible for the Pokrovsk direction, suffered the heaviest casualties during this period, with 43,709 killed, missing, and captured and 52,865 wounded.[13] These figures reflect the Russian military command’s prioritization of the Pokrovsk direction throughout 2025, as Russian forces suffered roughly 34 percent of their casualties in this direction during the first eight months of 2025. The Central Grouping of Forces’ 2nd Combined Arms Army (CAA) (Central Military District [CMD]) suffered 15,310 killed, missing, and captured and 16,260 wounded, and the 51st CAA (formerly 1st Donetsk People’s Republic Army Corps [DNR AC], Southern Military District [SMD]) suffered 13,000 killed, missing, and captured and 14,201 wounded — the heaviest casualties out of Russia’s CAAs. The 2nd CAA has been involved in fighting mainly south and east of Pokrovsk since October 2023 and the 51st CAA redeployed to the frontline east of Pokrovsk in early 2025 and is currently responsible for Russia’s penetration toward Dobropillya.[14] The Central Grouping of Forces’ 41st CAA, active in the Novopavlivka and Pokrovsk directions, suffered 7,544 killed, missing, and captured and 13,335 wounded. Russian forces have failed to seize Pokrovsk, Myrnohrad, Novopavlivka, or Druzhkivka after months of fighting despite sustaining significant casualties.

The documents reveal that Russia’s Northern Grouping of Forces, which eliminated much of Ukraine’s penetration into Kursk Oblast in early 2025 and is responsible for Russia’s ongoing efforts to create buffer zones in Sumy and Kharkiv oblasts, suffered 53,572 casualties, second only to the Central Grouping of Forces. Russian forces may have sustained a significant portion of these casualties during the intensified Russian effort to retake Kursk Oblast in February and March 2025. The Western Grouping of Forces, responsible for the Kupyansk, Lyman, and Borova directions, suffered 47,410 casualties. The 1st Guards Tank Army (Moscow Military District [MMD]), primarily active in the Lyman and Kupyansk directions, suffered casualties of 9,987 killed, missing, and captured and 11,411 wounded — the third highest figure among Russia’s CAAs fighting in Ukraine — underscoring the intensity of fighting in the Kupyansk and Lyman directions in recent months. The Western Grouping of Forces’ 20th CAA (MMD), active in the Borova and Lyman directions, suffered casualties of 6,410 killed, missing, and captured and 5,712 wounded. The Western Grouping of Forces has failed to seize any of the major settlements in its area of responsibility (AoR) — Kupyansk, Borova, and Lyman — in 2025.

Russian forces also sustained significant casualties in lower priority frontline areas in eastern and southern Ukraine. The Southern Grouping of Forces, active in the Kostyantynivka-Druzhkivka tactical area and the Siversk direction, suffered 32,740 casualties, with the 3rd CAA (formerly 2nd Luhansk People’s Republic [LNR] AC, Southern Military District [SMD]) around Siversk suffering 13,055 casualties, the highest in the grouping of forces. The Southern Grouping of Forces has made minimal progress since seizing Toretsk in June 2025. The Eastern Grouping of Forces, responsible for eastern Zaporizhia Oblast and the Velykomykhailivka direction, suffered 38,011 casualties, with the 5th CAA (Eastern Military District [EMD]), responsible for Russia’s grinding advance toward and into Dnipropetrovsk Oblast, suffering 16,980 casualties, the highest in the grouping of forces. The documents indicate that fighting in the Dnepr Grouping of Forces’ AoR, which includes the Kherson direction and western Zaporizhia Oblast, remains relatively desultory amid ongoing Russian efforts to reactivate the frontline in western Zaporizhia Oblast with the Dnieper Grouping of Forces suffering 13,243 casualties.

Russian forces appear able and willing to sustain these casualty rates despite achieving limited tactical advances. A Russian insider source that has consistently provided accurate reports about changes in the Russian military command previously reported that the Russian MoD recruited 292,000 people between January 1 and September 15, 2025 — an average of 31,600 recruits per month.[15] The leaked documents indicate that Russian forces lost an estimated 281,550 casualties between January and August 2025 — an average of 35,193 casualties per month.[16] Russian casualty rates thus far in 2025 appear slightly higher than current monthly Russian recruiting rates, but Russian casualty rates have been decreasing over the last four months. The Russian General Staff may assume that casualty rates will continue to decrease in Ukraine if Russian forces can improve their ability to counter the kill zone, and this reasoning may explain why Russia is reportedly beginning to form a strategic reserve for future deployment.[17] ISW previously assessed that Russian casualty rates marginally decreased and gains became less costly during Summer 2025 compared to Fall 2024 and Spring 2025, likely due in part to Russia’s renewed emphasis on using UAVs to interdict Ukrainian ground lines of communication (GLOCs) in rear areas.[18] Russia has proven its ability to recruit enough people to sustain losses in Ukraine over the last three years while possibly beginning to generate a strategic reserve, and the Kremlin is unlikely to abandon or decrease the pace of operations in Ukraine so long as Russia can continue to more than sustain such losses.

Key Takeaways

1. The Kremlin continues its reflective control campaign aimed at preventing the US from selling Tomahawk missiles to Ukraine.
2. Leaked Russian estimates of Russian killed in action (KIA) to wounded in action (WIA) rates in Ukraine underscore the impact of increased tactical drone usage in Ukraine and the extent to which drones complicate ground advances and casualty evacuation.
3. The leaked estimates indicate that Russian forces suffered their highest casualties in the Pokrovsk, Kupyansk, and Lyman directions between January and August 2025, reflecting command prioritization of these sectors of the front.
4. Russian forces appear able and willing to sustain these casualty rates despite achieving limited tactical advances.
5. European states continue to provide humanitarian and military aid to Ukraine and conclude joint agreements with Ukraine’s defense industrial base (DIB).
6. The Russian military command reportedly appointed Former Commander of the Russian Force Grouping in Syria Lieutenant General Sergei Kisel as the deputy commander of the Northern Grouping of Forces.
7. Ukrainian forces advanced near Novopavlivka and Velykomykhailivka. Russian forces advanced in eastern Zaporizhia Oblast, the Kostyantynivka-Druzhkivka and Dobropillya tactical areas and near Siversk, Pokrovsk, and Novopavlivka.