diff --git a/tools/iio/iio_utils.c b/tools/iio/iio_utils.c
index 55272fef3b50..d60a252577f0 100644
--- a/tools/iio/iio_utils.c
+++ b/tools/iio/iio_utils.c
@@ -546,6 +546,10 @@ 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++;