diff --git a/partitions.csv b/partitions.csv
index 131f3fd..73026ac 100644
--- a/partitions.csv
+++ b/partitions.csv
@@ -1,12 +1,16 @@
 # ESP-IDF partition table: A/B OTA app slots + LittleFS storage.
 #
-# Sized for a 4MB flash module (TODO: adjust once real flash size and
-# firmware image size are known).
+# Sized for the real 8MB flash module -- confirmed against actual
+# hardware via `esptool flash_id` (2026-07-12), not assumed from docs;
+# the previous 4MB layout left half the chip's flash unallocated. Extra
+# space went mostly to the OTA slots (headroom for future sensor
+# drivers and Blockly-generated Lua growing the app image), with
+# `storage` absorbing the remainder rather than leaving flash unused.
 #
 # Name,     Type, SubType,   Offset,   Size, Flags
 nvs,        data, nvs,       0x9000,   0x6000,
 otadata,    data, ota,       0xf000,   0x2000,
 phy_init,   data, phy,       0x11000,  0x1000,
-ota_0,      app,  ota_0,     0x20000,  0x180000,
-ota_1,      app,  ota_1,     0x1A0000, 0x180000,
-storage,    data, littlefs,  0x320000, 0xE0000,
+ota_0,      app,  ota_0,     0x20000,  0x300000,
+ota_1,      app,  ota_1,     0x320000, 0x300000,
+storage,    data, littlefs,  0x620000, 0x1E0000,
diff --git a/sdkconfig.defaults b/sdkconfig.defaults
index 08bac24..a4d2bab 100644
--- a/sdkconfig.defaults
+++ b/sdkconfig.defaults
@@ -5,9 +5,10 @@
 CONFIG_PARTITION_TABLE_CUSTOM=y
 CONFIG_PARTITION_TABLE_CUSTOM_FILENAME="partitions.csv"
 
-# Matches the 4MB layout assumed in partitions.csv (TODO: adjust both
-# together once real hardware's actual flash size is confirmed).
-CONFIG_ESPTOOLPY_FLASHSIZE_4MB=y
+# Matches the real 8MB flash (confirmed via `esptool flash_id` against
+# actual hardware, 2026-07-12) and partitions.csv's layout -- keep both
+# in sync if either changes.
+CONFIG_ESPTOOLPY_FLASHSIZE_8MB=y
 
 # IPv6 is required (not just the ESP-IDF default) -- transport/commissioning
 # requests a link-local IPv6 address once Wi-Fi STA connects. Explicit here