diff --git a/calculate-version.sh b/calculate-version.sh
new file mode 100755
index 0000000..1c48bf6
--- /dev/null
+++ b/calculate-version.sh
@@ -0,0 +1,95 @@
+#!/bin/bash
+
+# RegEx source:
+# https://web.archive.org/web/20221230095605/https://semver.org/#is-there-a-suggested-regular-expression-regex-to-check-a-semver-string
+SEMVER_REGEX='^(?P<major>0|[1-9]\d*)\.(?P<minor>0|[1-9]\d*)\.(?P<patch>0|[1-9]\d*)(?:-(?P<prerelease>(?:0|[1-9]\d*|\d*[a-zA-Z-][0-9a-zA-Z-]*)(?:\.(?:0|[1-9]\d*|\d*[a-zA-Z-][0-9a-zA-Z-]*))*))?(?:\+(?P<buildmetadata>[0-9a-zA-Z-]+(?:\.[0-9a-zA-Z-]+)*))?$'
+
+# Get the most recent tag in Git.
+tag=$(git describe --tags --abbrev=0 2>/dev/null)
+
+# If there are no tags, use 0.0.0
+if [ -z "$tag" ]
+then
+	tag=0.0.0
+fi
+
+# If the most recent tag is not a valid semantic version, rewind until we find one.
+while ! (echo $tag | perl -p -e 's/^v//i' | perl -ne "/$SEMVER_REGEX/ && (\$found=1); END {exit !\$found}")
+do
+	# # Get the hash for the most recent tag
+	tag_hash=$(git rev-list -n 1 $tag)
+
+	# Get the hash for the commit before the latest tag
+	previous_tag_hash=$(git rev-list $tag_hash | sed '2q;d')
+
+	# Rewind commits to the previous tag.
+	while (git describe --tags $previous_tag_hash 2>/dev/null | perl -ne '/.+?-\d+-g[[:xdigit:]]{7}$/ && ($found=1); END {exit !$found}')
+	do
+		tag_hash=$previous_tag_hash
+		previous_tag_hash=$(git rev-list $tag_hash | sed '2q;d')
+		# If we've reached the beginning of the commit history, break out of the
+		# loop. This should never happen.
+		if [ -z "$previous_tag_hash" ]
+		then
+			break
+		fi
+	done
+	# Get the tag, or return 0.0.0 if there are no tags or if we've reached the
+	# end of the commit history.
+	tag=$(git describe --tags $previous_tag_hash --abbrev=0 2>/dev/null || echo 0.0.0)
+done
+
+# Strip the leading 'v' from the tag, if it exists.
+VERSION=$(echo $tag | perl -p -e 's/^v//i')
+
+# Get the number of commits since the last valid tag.
+if [ "$tag" == "0.0.0" ]
+then
+	commits=$(git rev-list --count --no-merges HEAD)
+else
+	commits=$(git rev-list --count --no-merges $tag..HEAD)
+fi
+
+short_hash=$(git rev-parse --short HEAD)
+
+# If any tracked files have been modified, add a hash of the diff to the
+# version.
+drift_digest=$(git status --porcelain | perl -ne '/^\s?(M|A|D)/ && ($found=1); END {exit !$found}' && git diff HEAD | sha1sum | awk '{print $1}')
+
+# Determine if the version already has metadata.
+has_metadata=$(echo $VERSION | perl -ne '/\+/ && ($found=1); END {exit !$found}' && echo 1 || echo 0)
+
+# Add commit count and hash to the version if there are any commits since the
+# last tag.
+if [ $commits -gt 0 ]
+then
+	# If the version already has metadata, add a dash. Otherwise, add a plus.
+	if [ $has_metadata -eq 0 ]
+	then
+		VERSION=$VERSION+
+		has_metadata=1
+	else
+		VERSION=$VERSION-
+	fi
+	# Add the g prefix to the hash to indicate that it is a Git hash.
+	# Just like `git describe --tags` does.
+	VERSION=$VERSION$commits-g$short_hash
+fi
+
+# Add a hash of the diff to the version if there are any tracked files that
+# have been modified.
+if [ -n "$drift_digest" ]
+then
+	# If the version already has metadata, add a dash. Otherwise, add a plus.
+	if [ $has_metadata -eq 0 ]
+	then
+		VERSION=$VERSION+
+		has_metadata=1
+	else
+		VERSION=$VERSION-
+	fi
+	VERSION=$VERSION$drift_digest
+fi
+
+# Print the version.
+echo -n $VERSION