diff --git a/maths/binary_to_decimal.rb b/maths/binary_to_decimal.rb
new file mode 100644
index 0000000..af4c7b8
--- /dev/null
+++ b/maths/binary_to_decimal.rb
@@ -0,0 +1,26 @@
+=begin
+
+For any binary number of n digits i.e dn-1 ... d3 d2 d1 d0
+The equivalent decimal number is equal to the sum of binary digits (dn) times their power of 2 (2n):
+decimal = d0×2^0 + d1×2^1 + d2×2^2 + ...
+
+=end
+
+def binary_to_decimal(n)
+    decimal = 0
+    base = 1
+    until n.zero?
+        x = n % 10
+        n /= 10
+        decimal += x * base
+        base *= 2
+    end
+    return decimal
+end
+    
+puts "Decimal value of 110011 is " + binary_to_decimal(110011).to_s
+# Decimal value of 110011 is 51
+puts "Decimal value of 11110 is " + binary_to_decimal(11110).to_s
+# Decimal value of 11110 is 30
+puts "Decimal value of 101 is " + binary_to_decimal(101).to_s
+# Decimal value of 101 is 5