diff --git a/maths/armstrong_numbers.py b/maths/armstrong_numbers.py
index 26709b428b78..48afd8bea182 100644
--- a/maths/armstrong_numbers.py
+++ b/maths/armstrong_numbers.py
@@ -1,3 +1,5 @@
+import math
+
 """
 An Armstrong number is equal to the sum of its own digits each raised to the
 power of the number of digits.
@@ -29,9 +31,8 @@ def armstrong_number(n: int) -> bool:
     number_of_digits = 0
     temp = n
     # Calculation of digits of the number
-    while temp > 0:
-        number_of_digits += 1
-        temp //= 10
+    number_of_digits = math.floor(math.log10(temp)) + 1
+
     # Dividing number into separate digits and find Armstrong number
     temp = n
     while temp > 0: