diff --git a/include/util.h b/include/util.h
index 8e65e6d61..9cb861dd9 100644
--- a/include/util.h
+++ b/include/util.h
@@ -6,4 +6,9 @@
  */
 int wrap(int i, int max);
 
+/**
+ * Count number of digits in int
+ */
+int numlen(int n);
+
 #endif
diff --git a/sway/util.c b/sway/util.c
index 9a59ddf91..ed6d033fe 100644
--- a/sway/util.c
+++ b/sway/util.c
@@ -3,3 +3,13 @@
 int wrap(int i, int max) {
 	return ((i % max) + max) % max;
 }
+
+int numlen(int n) {
+	if (n >= 1000000) return 7;
+	if (n >= 100000) return 6;
+	if (n >= 10000) return 5;
+	if (n >= 1000) return 4;
+	if (n >= 100) return 3;
+	if (n >= 10) return 2;
+	return 1;
+}
diff --git a/swaygrab/main.c b/swaygrab/main.c
index 681a6da42..2c6cf2dd6 100644
--- a/swaygrab/main.c
+++ b/swaygrab/main.c
@@ -8,21 +8,12 @@
 #include <time.h>
 #include "log.h"
 #include "ipc-client.h"
+#include "util.h"
 
 void sway_terminate(void) {
 	exit(EXIT_FAILURE);
 }
 
-int numlen(int n) {
-	if (n >= 1000000) return 7;
-	if (n >= 100000) return 6;
-	if (n >= 10000) return 5;
-	if (n >= 1000) return 4;
-	if (n >= 100) return 3;
-	if (n >= 10) return 2;
-	return 1;
-}
-
 void grab_and_apply_magick(const char *file, const char *output,
 		int socketfd, int raw) {
 	uint32_t len = strlen(output);