diff --git a/.gitignore b/.gitignore
index 5b169b0f..9f544835 100644
--- a/.gitignore
+++ b/.gitignore
@@ -13,3 +13,4 @@ build/
 # host-test stand-ins for the two generated headers
 !test/stub/html_data.h
 !test/stub/version.h
+.vscode
diff --git a/Makefile b/Makefile
index 5ebd9ddf..aa31af35 100644
--- a/Makefile
+++ b/Makefile
@@ -64,6 +64,9 @@ endif
 # is built, including the tools/ subdirectory.
 all: create_build_dir $(VERSION_HEADER) $(MACHINE_SRC) $(SUBDIRS) $(BUILDDIR)/rtlplayground-$(FILENAME_EXTENSION).bin
 
+bank_size:
+	tools/bank_occupancy.sh "$(MACHINE)"
+
 create_build_dir:
 	mkdir -p "$(BUILDDIR)"
 	mkdir -p "$(BUILDDIR)/uip"
diff --git a/tools/bank_occupancy.sh b/tools/bank_occupancy.sh
new file mode 100755
index 00000000..c0dece81
--- /dev/null
+++ b/tools/bank_occupancy.sh
@@ -0,0 +1,21 @@
+#!/bin/bash
+MACHINE="$1"
+if [[ ! -s output-main/rtlplayground.map ]]; then
+    original_branch=$(git branch --show-current)
+    #trap 'git switch "$original_branch"' EXIT
+    git switch main && make CI=1 MACHINE="$MACHINE" BUILDDIR=output-main
+    git switch "$original_branch"
+fi
+source <(sed -rn 's/^([XCD]SEG|(BANK[0-9])).*=\s+([0-9]+)\. bytes.*$/main_\1=\3/p' output-main/rtlplayground.map | sort -u)
+if [[ ! -s "output/$MACHINE/rtlplayground.map" ]]; then
+    make CI=1 MACHINE="$MACHINE"
+fi
+source <(sed -rn 's/^([XCD]SEG|(BANK[0-9])).*=\s+([0-9]+)\. bytes.*$/branch_\1=\3/p' output/"$MACHINE"/rtlplayground.map | sort -u)
+
+printf '%-20s %-20s %-20s %-20s\n' "segment" "main" "branch" "change"
+printf '%-20s %-20s %-20s %-20s\n' "BANK1" "$main_BANK1" "$branch_BANK1" "$(($branch_BANK1-$main_BANK1))"
+printf '%-20s %-20s %-20s %-20s\n' "BANK2" "$main_BANK2" "$branch_BANK2" "$(($branch_BANK2-$main_BANK2))"
+printf '%-20s %-20s %-20s %-20s\n' "BANK3" "$main_BANK3" "$branch_BANK3" "$(($branch_BANK3-$main_BANK3))"
+printf '%-20s %-20s %-20s %-20s\n' "CSEG" "$main_CSEG" "$branch_CSEG" "$(($branch_CSEG-$main_CSEG))"
+printf '%-20s %-20s %-20s %-20s\n' "DSEG" "$main_DSEG" "$branch_DSEG" "$(($branch_DSEG-$main_DSEG))"
+printf '%-20s %-20s %-20s %-20s\n' "XSEG" "$main_XSEG" "$branch_XSEG" "$(($branch_XSEG-$main_XSEG))"