diff --git a/lib/binary_to_decimal.rb b/lib/binary_to_decimal.rb
index 439e8c6..e594f08 100644
--- a/lib/binary_to_decimal.rb
+++ b/lib/binary_to_decimal.rb
@@ -5,5 +5,13 @@
 # Calculate  and return the decimal value for this binary number using
 # the algorithm you devised in class.
 def binary_to_decimal(binary_array)
-  raise NotImplementedError
+  decimal = 0
+  iterator = 7
+
+  binary_array.each do |digit|
+    decimal += digit * 2 ** iterator
+    iterator -= 1
+  end
+
+  return decimal
 end