diff --git a/tools/iio/iio_utils.c b/tools/iio/iio_utils.c
index aadee6d34c74c112f84be5977f23135e34ee0d20..8d35893b2fa856741d8098da41add733c2ce25cb 100644
--- a/tools/iio/iio_utils.c
+++ b/tools/iio/iio_utils.c
@@ -547,6 +547,10 @@ static int calc_digits(int num)
 {
 	int count = 0;
 
+	/* It takes a digit to represent zero */
+	if (!num)
+		return 1;
+
 	while (num != 0) {
 		num /= 10;
 		count++;