C++ Mortgage Calculator/user inputs loan, interenst, term

Your code gets:

      Your Monthly Payment Amount is: $1167.15

According to http://www.bbc.co.uk/homes/property/mortgagecalculator.shtml a £20,000 loan payed over 30 years at 5.75% should be a monthly payment of £1,178.60. Do a right-click and view source and you can see how they do the calculation.

      R = R / 100;
      var P = ((A*R)/12) * (1/(1-(Math.pow(1/(1+R),T))));

I'm too lazy/ignorant about finance to know which formula is right. Does the BBC formula match your expectations, or do you reckon your formula is right (and you were simply asking about looping, input etc)?

>>>> I'm too lazy/ignorant about finance to know which formula is right.
The difference is that

        (1/(1-(Math.pow(1/(1+R),T));

makes a calculation on a yearly base (T = 30, R = 0.0575)  while

        (1 - pow(1+Ci,-t));

is based on a monthly interest (Ci = 0.0575/12 = 0.0047916666) what is better hence the lower payments.

Thanks, Alex.

<parochial_comment locale="uk">
I've got a feeling that I'm going to need to wise up about mortgages soon :-(
</parochial_comment>

check source forge lots of working solution is available

www.sourceforge.net

>>>> check source forge lots of working solution is available
I am convinced that the EE strategy to help with solutions for assignments but not to give a full solution is better for the asker.  If he/she needs to explain some statements or answer questions to the design, the student will most likely fail if sthe solution was copied but not worked out. Moreover, it is easy for a teacher to slightly change the requirements and find out which solutions were copied and which were worked out.

Regards, Alex
 

I am so sorry....posted the wrong code last night, here is the code i intended to post...


#include "stdafx.h"
#include "math.h"
#include <iostream>


using std::cout;
using std::endl;

int main()
{
  int a;                              //Amount of the loan
  double i;                              // Interest rate of the loan
  int y;                              //term loan will be financed for
  double mpay;                        //variable for ouputting your monthly payment
  double Ci= i/(12*100);            //converts interest for calculation
  int t = y*12;                               //convert term into months for calculation

  char letter = 'e';            //character to exit program

  cout<< "***********************************"; cout<<endl;
  cout<< "WELCOME TO THE MORTGAGE CALCULATOR"; cout<<endl;
  cout<< "***********************************"; cout<<endl;cout<<endl;

 while (true)
  {
        cout<< "Please enter Amount of Mortgage (no commas ie. 200000): ";      //prompt user for mortgage
            cin>> a;

         cout<< "Please enter your interest rate: "; //prompt user for interest
                  cin>> i;
                  
         cout<< "Please enter the term of your loan in years (ie. 30): ";      //prompt user for term of loan
                  cin>> y;
                  

 
 
  cout<<"***************************************************";cout<<endl;
  cout<< "With a mortgage of: $"<<a; cout<<endl;
  cout<< "An interest rate of: "<<i;cout<<"%";cout<<endl;
  cout<< "Over a term of: "<<y;cout<<"years";cout<<endl;
  cout<< "Your Monthly Payment Amount is: $"<< mpay;cout<<endl; //prints out montyly payment amount
  cout<<"***************************************************";cout<<endl;cout<<endl;
  cout<< "Press C to calculate another payment, or E to exit: ";
  cout<<endl;
      cin>> letter;
            if ((letter=='e')||(letter=='E')) break;

 mpay = (a * Ci) / (1 - pow(1+Ci,-t)); //Formula to figure mortgage payment amount
            cout<< endl;

  }
 
 
  cout<< endl;
  cout<< endl;
    system("PAUSE");
  return 0;
}

I did figure it out late last night and have posted a working code in case anyone else runs into the same issues:

did not have: using std::cin;

needed to move the declaration of interest/monthly conversion underneath the user input area

and last i moved the calculation for the mortgage payment inside the loop.

not sure if the location of the interest/conversion to months matters but i was trying so many different things to get the code to compile once it finally worked i just left it......believe it or not this simple mortgage calculator code took me about 4 hrs total..ughhhh  

working code:

#include "stdafx.h"
#include "math.h"
#include <iostream>


using std::cout;
using std::endl;
using std::cin;

int main()
{
  int a;                              //Amount of the loan
  double i;                              // Interest rate of the loan
  int y;                              //term loan will be financed for
  double mpay;                        //variable for ouputting your monthly payment
  char letter = 'e';            //character to exit program

  cout<< "***********************************"; cout<<endl;

  cout<< "WELCOME TO THE MORTGAGE CALCULATOR"; cout<<endl;

  cout<< "***********************************"; cout<<endl;cout<<endl;

 while (true)
  {
        cout<< "Please enter Amount of Mortgage (no commas ie. 200000): ";      //prompt user for mortgage
            cin>> a;

         cout<< "Please enter your interest rate: "; //prompt user for interest
                  cin>> i;
                  
         cout<< "Please enter the term of your loan in years (ie. 30): ";      //prompt user for term of loan
                  cin>> y;
                  
  double Ci= i/(12*100); //converts interest for calculation
  int t = y*12;               //convert term into months for calculation

  mpay = (a * Ci) / (1 - pow(1+Ci,-t)); //Formula to figure mortgage payment amount
 
  cout<<"***************************************************";cout<<endl;
  cout<< "With a mortgage of: $"<<a; cout<<endl;
  cout<< "An interest rate of: "<<i;cout<<"%";cout<<endl;
  cout<< "Over a term of: "<<y;cout<<"years";cout<<endl;
  cout<< "Your Monthly Payment Amount is: $"<< mpay;cout<<endl; //prints out montyly payment amount
  cout<<"***************************************************";cout<<endl;cout<<endl;
  cout<< "Press C to calculate another payment, or E to exit: ";
  cout<<endl;
      cin>> letter;
            if ((letter=='e')||(letter=='E')) break;
            cout<< endl;

  }
 
 
  cout<< endl;
  cout<< endl;
    system("PAUSE");
  return 0;
}

so whats not working now ? maybe its just the formula you are using.

----code snip ---
cout<< "Press C to calculate another payment, or E to exit: ";
 cout<<endl;
      cin>> letter;
            if ((letter=='e')||(letter=='E')) break;
            cout<< endl;
----snip end--------
also in the above
it will go for calculating another payment even if X,Y or Z is pressed , only on e or E it exits
(typically they use 'q' or 'Q' to quit .,. its not important as part of this assignment but its better for coders to try to follow the principle of least surprise :)

The code is working properly now but I don't know how to close out the question....lol  I just posted the finished code in case anybody else has issues or questions along the same line.  

http://sourceforge.net/projects/mortgage/ check this a nice and descent mortgage calculator

aatrish2001
   check the response by itsmeandnobodyelse above

alacy
   you can probably ask for your points to be refunded somewhere .. dunno where but it is there just look around .
   

>>>> The code is working properly now but I don't
>>>> know how to close out the question....
If you think that one or more comments have helped you to fulfil your task you should accept these comments as a solution. Choose either accept or multiple accept (if the latter beginning with the comment which helped most).

If you think that none of the answers had helped you might ask a (free) question for that in the General Community Support TA which you can reach via the SUPPORT link in the top right of any page. But I think there have been too much good hints in that thread to get a full refund.

Regards, Alex

I didn't even know you get only certain amount of points, i originally signed up for the solutions that were already posted.  This is the first question i have posted, i love this site...it has saved me so much time i payed for unlimited access and it has not let me down yet....


thanks again for everyones help