diff --git a/src/common/system.cpp b/src/common/system.cpp
index 7af792db44c..cf032adfced 100644
--- a/src/common/system.cpp
+++ b/src/common/system.cpp
@@ -11,19 +11,25 @@
 #include <util/string.h>
 #include <util/time.h>
 
-#ifndef WIN32
-#include <sys/stat.h>
-#else
-#include <compat/compat.h>
+#ifdef WIN32
 #include <codecvt>
+#include <compat/compat.h>
+#include <windows.h>
+#else
+#include <sys/stat.h>
+#include <unistd.h>
 #endif
 
 #ifdef HAVE_MALLOPT_ARENA_MAX
 #include <malloc.h>
 #endif
 
+#include <algorithm>
+#include <cstddef>
+#include <cstdint>
 #include <cstdlib>
 #include <locale>
+#include <optional>
 #include <stdexcept>
 #include <string>
 #include <thread>
@@ -105,6 +111,17 @@ int GetNumCores()
     return std::thread::hardware_concurrency();
 }
 
+std::optional<size_t> GetTotalRAM()
+{
+    auto clamp{[](uint64_t v) { return size_t(std::min(v, uint64_t{std::numeric_limits<size_t>::max()})); }};
+#ifdef WIN32
+    if (MEMORYSTATUSEX m{}; (m.dwLength = sizeof(m), GlobalMemoryStatusEx(&m))) return clamp(m.ullTotalPhys);
+#elif defined(__linux__) || defined(__APPLE__)
+    if (long p{sysconf(_SC_PHYS_PAGES)}, s{sysconf(_SC_PAGESIZE)}; p > 0 && s > 0) return clamp(1ULL * p * s);
+#endif
+    return std::nullopt;
+}
+
 // Obtain the application startup time (used for uptime calculation)
 int64_t GetStartupTime()
 {
diff --git a/src/common/system.h b/src/common/system.h
index a4b56be9ac9..2184f1d4c9e 100644
--- a/src/common/system.h
+++ b/src/common/system.h
@@ -9,6 +9,7 @@
 #include <bitcoin-build-config.h> // IWYU pragma: keep
 
 #include <cstdint>
+#include <optional>
 #include <string>
 
 // Application startup time (used for uptime calculation)
@@ -29,4 +30,9 @@ void runCommand(const std::string& strCommand);
  */
 int GetNumCores();
 
+/**
+ * Return the total RAM available on the current system, if detectable.
+ */
+std::optional<size_t> GetTotalRAM();
+
 #endif // BITCOIN_COMMON_SYSTEM_H
diff --git a/src/init.cpp b/src/init.cpp
index 4ff57a34171..2f518eba14c 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -1767,6 +1767,7 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
     // ********************************************************* Step 7: load block chain
 
     // cache size calculations
+    node::LogOversizedDbCache(args);
     const auto [index_cache_sizes, kernel_cache_sizes] = CalculateCacheSizes(args, g_enabled_filter_types.size());
 
     LogInfo("Cache configuration:");
diff --git a/src/node/caches.cpp b/src/node/caches.cpp
index d5d69fc2044..e4a5e6d17e3 100644
--- a/src/node/caches.cpp
+++ b/src/node/caches.cpp
@@ -5,9 +5,12 @@
 #include <node/caches.h>
 
 #include <common/args.h>
+#include <common/system.h>
 #include <index/txindex.h>
 #include <kernel/caches.h>
 #include <logging.h>
+#include <node/interface_ui.h>
+#include <tinyformat.h>
 #include <util/byte_units.h>
 
 #include <algorithm>
@@ -23,16 +26,20 @@ static constexpr size_t MAX_FILTER_INDEX_CACHE{1024_MiB};
 static constexpr size_t MAX_32BIT_DBCACHE{1024_MiB};
 
 namespace node {
+size_t CalculateDbCacheBytes(const ArgsManager& args)
+{
+    if (auto db_cache{args.GetIntArg("-dbcache")}) {
+        if (*db_cache < 0) db_cache = 0;
+        const uint64_t db_cache_bytes{SaturatingLeftShift<uint64_t>(*db_cache, 20)};
+        constexpr auto max_db_cache{sizeof(void*) == 4 ? MAX_32BIT_DBCACHE : std::numeric_limits<size_t>::max()};
+        return std::max<size_t>(MIN_DB_CACHE, std::min<uint64_t>(db_cache_bytes, max_db_cache));
+    }
+    return DEFAULT_DB_CACHE;
+}
+
 CacheSizes CalculateCacheSizes(const ArgsManager& args, size_t n_indexes)
 {
-    // Convert -dbcache from MiB units to bytes. The total cache is floored by MIN_DB_CACHE and capped by max size_t value.
-    size_t total_cache{DEFAULT_DB_CACHE};
-    if (std::optional<int64_t> db_cache = args.GetIntArg("-dbcache")) {
-        if (*db_cache < 0) db_cache = 0;
-        uint64_t db_cache_bytes = SaturatingLeftShift<uint64_t>(*db_cache, 20);
-        constexpr auto max_db_cache{sizeof(void*) == 4 ? MAX_32BIT_DBCACHE : std::numeric_limits<size_t>::max()};
-        total_cache = std::max<size_t>(MIN_DB_CACHE, std::min<uint64_t>(db_cache_bytes, max_db_cache));
-    }
+    size_t total_cache{CalculateDbCacheBytes(args)};
 
     IndexCacheSizes index_sizes;
     index_sizes.tx_index = std::min(total_cache / 8, args.GetBoolArg("-txindex", DEFAULT_TXINDEX) ? MAX_TX_INDEX_CACHE : 0);
@@ -44,4 +51,15 @@ CacheSizes CalculateCacheSizes(const ArgsManager& args, size_t n_indexes)
     }
     return {index_sizes, kernel::CacheSizes{total_cache}};
 }
+
+void LogOversizedDbCache(const ArgsManager& args) noexcept
+{
+    if (const auto total_ram{GetTotalRAM()}) {
+        const size_t db_cache{CalculateDbCacheBytes(args)};
+        if (ShouldWarnOversizedDbCache(db_cache, *total_ram)) {
+            InitWarning(bilingual_str{tfm::format(_("A %zu MiB dbcache may be too large for a system memory of only %zu MiB."),
+                        db_cache >> 20, *total_ram >> 20)});
+        }
+    }
+}
 } // namespace node
diff --git a/src/node/caches.h b/src/node/caches.h
index f24e9cc9103..c0ef41ec696 100644
--- a/src/node/caches.h
+++ b/src/node/caches.h
@@ -27,6 +27,13 @@ struct CacheSizes {
     kernel::CacheSizes kernel;
 };
 CacheSizes CalculateCacheSizes(const ArgsManager& args, size_t n_indexes = 0);
+constexpr bool ShouldWarnOversizedDbCache(size_t dbcache, size_t total_ram) noexcept
+{
+    const size_t cap{(total_ram < 2048_MiB) ? DEFAULT_DB_CACHE : (total_ram / 100) * 75};
+    return dbcache > cap;
+}
+
+void LogOversizedDbCache(const ArgsManager& args) noexcept;
 } // namespace node
 
 #endif // BITCOIN_NODE_CACHES_H
diff --git a/src/test/CMakeLists.txt b/src/test/CMakeLists.txt
index a818dba7205..c963afff351 100644
--- a/src/test/CMakeLists.txt
+++ b/src/test/CMakeLists.txt
@@ -25,6 +25,7 @@ add_executable(test_bitcoin
   blockmanager_tests.cpp
   bloom_tests.cpp
   bswap_tests.cpp
+  caches_tests.cpp
   chainstate_write_tests.cpp
   checkqueue_tests.cpp
   cluster_linearize_tests.cpp
diff --git a/src/test/caches_tests.cpp b/src/test/caches_tests.cpp
new file mode 100644
index 00000000000..3086118fc7e
--- /dev/null
+++ b/src/test/caches_tests.cpp
@@ -0,0 +1,40 @@
+#include <node/caches.h>
+#include <util/byte_units.h>
+
+#include <boost/test/unit_test.hpp>
+
+using namespace node;
+
+BOOST_AUTO_TEST_SUITE(caches_tests)
+
+BOOST_AUTO_TEST_CASE(oversized_dbcache_warning)
+{
+    // memory restricted setup - cap is DEFAULT_DB_CACHE (450 MiB)
+    BOOST_CHECK(!ShouldWarnOversizedDbCache(/*dbcache=*/4_MiB, /*total_ram=*/1024_MiB));    // Under cap
+    BOOST_CHECK( ShouldWarnOversizedDbCache(/*dbcache=*/512_MiB, /*total_ram=*/1024_MiB));  // At cap
+    BOOST_CHECK( ShouldWarnOversizedDbCache(/*dbcache=*/1500_MiB, /*total_ram=*/1024_MiB)); // Over cap
+
+    // 2 GiB RAM - cap is 75%
+    BOOST_CHECK(!ShouldWarnOversizedDbCache(/*dbcache=*/1500_MiB, /*total_ram=*/2048_MiB)); // Under cap
+    BOOST_CHECK( ShouldWarnOversizedDbCache(/*dbcache=*/1600_MiB, /*total_ram=*/2048_MiB)); // Over cap
+
+    if constexpr (SIZE_MAX == UINT64_MAX) {
+        // 4 GiB RAM - cap is 75%
+        BOOST_CHECK(!ShouldWarnOversizedDbCache(/*dbcache=*/2500_MiB, /*total_ram=*/4096_MiB)); // Under cap
+        BOOST_CHECK( ShouldWarnOversizedDbCache(/*dbcache=*/3500_MiB, /*total_ram=*/4096_MiB)); // Over cap
+
+        // 8 GiB RAM - cap is 75%
+        BOOST_CHECK(!ShouldWarnOversizedDbCache(/*dbcache=*/6000_MiB, /*total_ram=*/8192_MiB)); // Under cap
+        BOOST_CHECK( ShouldWarnOversizedDbCache(/*dbcache=*/7000_MiB, /*total_ram=*/8192_MiB)); // Over cap
+
+        // 16 GiB RAM - cap is 75%
+        BOOST_CHECK(!ShouldWarnOversizedDbCache(/*dbcache=*/10'000_MiB, /*total_ram=*/16384_MiB)); // Under cap
+        BOOST_CHECK( ShouldWarnOversizedDbCache(/*dbcache=*/15'000_MiB, /*total_ram=*/16384_MiB)); // Over cap
+
+        // 32 GiB RAM - cap is 75%
+        BOOST_CHECK(!ShouldWarnOversizedDbCache(/*dbcache=*/20'000_MiB, /*total_ram=*/32768_MiB)); // Under cap
+        BOOST_CHECK( ShouldWarnOversizedDbCache(/*dbcache=*/30'000_MiB, /*total_ram=*/32768_MiB)); // Over cap
+    }
+}
+
+BOOST_AUTO_TEST_SUITE_END()
diff --git a/src/test/system_tests.cpp b/src/test/system_tests.cpp
index dec4d418290..53db32007ee 100644
--- a/src/test/system_tests.cpp
+++ b/src/test/system_tests.cpp
@@ -8,6 +8,8 @@
 #include <common/run_command.h>
 #include <univalue.h>
 
+#include <common/system.h>
+
 #ifdef ENABLE_EXTERNAL_SIGNER
 #include <util/subprocess.h>
 #endif // ENABLE_EXTERNAL_SIGNER
@@ -16,6 +18,17 @@
 
 BOOST_FIXTURE_TEST_SUITE(system_tests, BasicTestingSetup)
 
+BOOST_AUTO_TEST_CASE(total_ram)
+{
+    BOOST_CHECK_GE(GetTotalRAM(), 1000_MiB);
+
+    if constexpr (SIZE_MAX == UINT64_MAX) {
+        // Upper bound check only on 64-bit: 32-bit systems can reasonably have max memory,
+        // but extremely large values on 64-bit likely indicate detection errors
+        BOOST_CHECK_LT(GetTotalRAM(), 10'000'000_MiB); // >10 TiB memory is unlikely
+    }
+}
+
 #ifdef ENABLE_EXTERNAL_SIGNER
 
 BOOST_AUTO_TEST_CASE(run_command)