diff --git a/CPP/binaryToDecimalAndViceversa.cpp b/CPP/binaryToDecimalAndViceversa.cpp
new file mode 100644
index 000000000..389710ff9
--- /dev/null
+++ b/CPP/binaryToDecimalAndViceversa.cpp
@@ -0,0 +1,31 @@
+// convert binary to decimal
+
+#include <iostream>
+#include <cmath>
+
+using namespace std;
+
+// function prototype
+int convert(long long);
+
+int main() {
+  long long n;
+  cout << "Enter a binary number: ";
+  cin >> n;
+  cout << n << " in binary = " << convert(n) << " in decimal";
+  return 0;
+}
+
+// function definition
+int convert(long long n) {
+  int dec = 0, i = 0, rem;
+
+  while (n!=0) {
+    rem = n % 10;
+    n /= 10;
+    dec += rem * pow(2, i);
+    ++i;
+  }
+
+  return dec;
+}