Russian forces in Ukraine suffered a net loss of 116 square kilometers of controlled territory in April 2026 — the first such loss since Ukraine's August 2024 incursion into Russia's Kursk Oblast — the Institute for the Study of War (ISW) reported on 2 May. The Russian rate of advance has been steadily declining since November 2025, with the average daily Russian gain across the first four months of 2026 falling to 2.9 km² — down from 9.76 km² per day in the same period of 2025.
Russia's slowing tempo on the ground in Ukraine has been visible in independent battlefield mapping for months, with the same pressures — Ukrainian deep strikes, drone interdiction of Russian logistics, and Ukraine's expanding own deep-strike industry — eroding the offensive calculus the Kremlin built around brute mass. Every month, Russian forces' failure to convert manpower losses into territorial gain widens the gap between what the Kremlin claims about the war.
A 925 km² gap, year over year
ISW assessed Russian forces seized 1,443.35 km² between November 2025 and April 2026 — against 2,368.38 km² over the same six months a year earlier, a year-on-year drop of about 925 km².
The Institute flagged that the comparison is complicated by a Russian shift toward infiltration tactics through 2025, with small Russian groups penetrating into Ukrainian-held "gray zones" rather than seizing terrain outright. Including infiltrations, Russia's net April figure is 28.28 km² gained — but only because infiltrations papered over the 116 km² controlled-territory loss.
"The Kremlin uses Russian infiltration tactics in part to exaggerate Russian control of terrain"
That is ISW's direct framing in the 2 May assessment, with the think tank noting that Russian forces "do not control these infiltration areas, which are often collocated among Ukrainian positions in contested 'gray zones.'"
The Russian playbook, ISW writes, uses these incursions "in part to create the perception of continuous Russian advances across the front and to support Kremlin cognitive warfare efforts to exaggerate Russian successes."
Caveats: weather and methodology
ISW noted that part of the slowdown may be seasonal — eastern Ukraine's winter of 2025-2026 was about three degrees Fahrenheit (1.67°C) colder and significantly wetter than the previous winter, with rasputitsa mud degrading mechanized movement. In past years, Russian forces have stepped up advances in May and June as the ground dried out — whether that pattern returns in 2026 is unclear.
The think tank also said it had refined some area calculations in its mapping data, with no effect on previously assessed trendlines, and shifted to month-end-to-month comparisons going forward.
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