Comments on: Questions http://www.bretwhissel.net/blog Curiosities of a Rambling Mind Tue, 27 Oct 2009 13:01:38 -0600 http://wordpress.org/?v=2.8.4 hourly 1 By: Bret Whissel http://www.bretwhissel.net/blog/calculator/more-questions/comment-page-2/#comment-181 Bret Whissel Tue, 06 Oct 2009 18:22:30 +0000 http://www.bretwhissel.net/blog/?page_id=76#comment-181 Hi, gth48. The calculator is not designed to do the sort of calculation you're asking, as you're not actually performing an amortization. Instead of an amortization calculator, you just need some sort of an interest calculator. There are at least two questions to which you need to know the answers before you could make this calculation accurately: (1) How is the annual interest rate turned into a periodic (i.e., monthly) rate? (2) Is the interest compounded, and if so, on what basis? or is it simple interest? You can probably find some help for this calculation if you search for "compound interest calculator" or "simple interest calculator". Hi, gth48. The calculator is not designed to do the sort of calculation you’re asking, as you’re not actually performing an amortization. Instead of an amortization calculator, you just need some sort of an interest calculator.

There are at least two questions to which you need to know the answers before you could make this calculation accurately: (1) How is the annual interest rate turned into a periodic (i.e., monthly) rate? (2) Is the interest compounded, and if so, on what basis? or is it simple interest?

You can probably find some help for this calculation if you search for “compound interest calculator” or “simple interest calculator”.

]]> By: gth48 http://www.bretwhissel.net/blog/calculator/more-questions/comment-page-2/#comment-180 gth48 Sun, 04 Oct 2009 09:06:45 +0000 http://www.bretwhissel.net/blog/?page_id=76#comment-180 Brett, My apologies but I am needing some help, and cannot figure out how this would be entered..I am not that smartest student in the room...especially in Math. So here goes....a 25,000.00 loan ..no payments for 168 months, at a 8 percent interest would come out to how much? I am sure this is not rocket science..I just can't get it. Brett, My apologies but I am needing some help, and cannot figure out how this would be entered..I am not that smartest student in the room…especially in Math. So here goes….a 25,000.00 loan ..no payments for 168 months, at a 8 percent interest would come out to how much? I am sure this is not rocket science..I just can’t get it.

]]> By: Bret Whissel http://www.bretwhissel.net/blog/calculator/more-questions/comment-page-2/#comment-179 Bret Whissel Fri, 02 Oct 2009 19:17:51 +0000 http://www.bretwhissel.net/blog/?page_id=76#comment-179 Hi, Geo. I'm not familiar with this repayment scheme, and it seems like there are some details left out. I don't know of such a calculator, but it seems like the math for such a scheme wouldn't really require a specialized calculator. Hi, Geo. I’m not familiar with this repayment scheme, and it seems like there are some details left out. I don’t know of such a calculator, but it seems like the math for such a scheme wouldn’t really require a specialized calculator.

]]> By: geowithquestion http://www.bretwhissel.net/blog/calculator/more-questions/comment-page-2/#comment-178 geowithquestion Thu, 01 Oct 2009 17:49:30 +0000 http://www.bretwhissel.net/blog/?page_id=76#comment-178 Hi Bret, I've used your calculator more times than I can count over the last few years. Thanks for creating it. I am writing to request a calculator with different input parameters. There are loans out there (I have one with a credit card co. and am considering another with my bank) where your monthly payment is based on paying a percentage of the principle plus interest on the principle. For example, the one I have with the credit card is based on paying 1.5% of the principle plus 3.99% interest for the life of the loan. It's a fairly agressive pay down scheme that I like, but I cannot find a calculator with a payment schedule. Do you know if one? Would you considr creating one? Thanks and best wishes. Hi Bret,

I’ve used your calculator more times than I can count over the last few years. Thanks for creating it. I am writing to request a calculator with different input parameters. There are loans out there (I have one with a credit card co. and am considering another with my bank) where your monthly payment is based on paying a percentage of the principle plus interest on the principle. For example, the one I have with the credit card is based on paying 1.5% of the principle plus 3.99% interest for the life of the loan. It’s a fairly agressive pay down scheme that I like, but I cannot find a calculator with a payment schedule. Do you know if one? Would you considr creating one?
Thanks and best wishes.

]]> By: Bret Whissel http://www.bretwhissel.net/blog/calculator/more-questions/comment-page-2/#comment-177 Bret Whissel Wed, 30 Sep 2009 19:38:14 +0000 http://www.bretwhissel.net/blog/?page_id=76#comment-177 So if anyone has been following along and wonders about Viking's question, I have not been able to find a closed-form solution for calculating the number of payments. The equation eventually comes down to something in the form [ <i>ax + b = c<sup>x</sup></i> ] (solve for <i>x</i>). If there is a solution that does not involve iteration, I don't know of one. So if anyone has been following along and wonders about Viking’s question, I have not been able to find a closed-form solution for calculating the number of payments. The equation eventually comes down to something in the form [ ax + b = cx ] (solve for x). If there is a solution that does not involve iteration, I don’t know of one.

]]> By: viking http://www.bretwhissel.net/blog/calculator/more-questions/comment-page-2/#comment-176 viking Wed, 23 Sep 2009 20:23:46 +0000 http://www.bretwhissel.net/blog/?page_id=76#comment-176 Wish that I could edit my posts..... Forgot to mention that the amortization period is 36 months Wish that I could edit my posts…..
Forgot to mention that the amortization period is 36 months

]]> By: viking http://www.bretwhissel.net/blog/calculator/more-questions/comment-page-2/#comment-175 viking Wed, 23 Sep 2009 20:19:07 +0000 http://www.bretwhissel.net/blog/?page_id=76#comment-175 p.s. Not to sidetrack the issue, but the original problem is slightly different. In this case, I didn't know the Total Interest Paid, but instead the Total paid; per the example above: Total Paid= 8*$344.87+$8,460.79=$11,219.60 and I needed to find N. However, I realized that Total Interest Paid = Total paid-Principal=$11,219.60 - $10,500= $719.60. Thus, the two situations are basically the same. p.s. Not to sidetrack the issue, but the original problem is slightly different.

In this case, I didn’t know the Total Interest Paid, but instead the Total paid; per the example above:
Total Paid= 8*$344.87+$8,460.79=$11,219.60
and I needed to find N.

However, I realized that Total Interest Paid = Total paid-Principal=$11,219.60 – $10,500= $719.60.

Thus, the two situations are basically the same.

]]> By: viking http://www.bretwhissel.net/blog/calculator/more-questions/comment-page-2/#comment-174 viking Wed, 23 Sep 2009 20:13:20 +0000 http://www.bretwhissel.net/blog/?page_id=76#comment-174 OK. We can use the example above, strying to solve for N: Principal=$10,500; payments/year =12; Annual Rate=11.22%; Monthly Payment Amount= $344.87; Total Interest Paid=$719.60. Unknown: Number of Payments (N) (From your calculator, it turns out that N=8). However, I need the actual formula for N as a function of the known variables. Thanks in advance! OK. We can use the example above, strying to solve for N:

Principal=$10,500; payments/year =12; Annual Rate=11.22%; Monthly Payment Amount= $344.87; Total Interest Paid=$719.60.

Unknown: Number of Payments (N)

(From your calculator, it turns out that N=8).

However, I need the actual formula for N as a function of the known variables.

Thanks in advance!

]]> By: Bret Whissel http://www.bretwhissel.net/blog/calculator/more-questions/comment-page-2/#comment-173 Bret Whissel Wed, 23 Sep 2009 14:15:59 +0000 http://www.bretwhissel.net/blog/?page_id=76#comment-173 Hi, Viking. Yes, interest is accounted for in the Balloon Payment, as it's assumed that the Balloon Payment occurs one full payment cycle after the last Regular Payment. As for your first question regarding Total Interest Paid after N payments, before I can answer, I need to know what the known quantities are. (I.e., do you know the interest rate? the payment amount? the length of the amortization period? etc.) Hi, Viking. Yes, interest is accounted for in the Balloon Payment, as it’s assumed that the Balloon Payment occurs one full payment cycle after the last Regular Payment.

As for your first question regarding Total Interest Paid after N payments, before I can answer, I need to know what the known quantities are. (I.e., do you know the interest rate? the payment amount? the length of the amortization period? etc.)

]]> By: viking http://www.bretwhissel.net/blog/calculator/more-questions/comment-page-2/#comment-171 viking Wed, 23 Sep 2009 01:58:40 +0000 http://www.bretwhissel.net/blog/?page_id=76#comment-171 Ops, Bret you can delete my 2nd post. I just realized what you were doing; The last month's interest is included both in the Balloon payment and in the Total Interest Paid (this was a bit confusing) In your case: Total Paid= 7*$344.87+$8,805.65=$11,219.60 in my case: Total Paid= 8*$344.87+$8,460.79=$11,219.60 End results are the same :-). Ops, Bret you can delete my 2nd post.

I just realized what you were doing; The last month’s interest is included both in the Balloon payment and in the Total Interest Paid (this was a bit confusing)

In your case:
Total Paid= 7*$344.87+$8,805.65=$11,219.60
in my case:
Total Paid= 8*$344.87+$8,460.79=$11,219.60
End results are the same :-) .

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