Talk:Amortization calculator

Seems this page was created as spam and that's why it keeps *getting* spammed. It shouldn't exist. It's not a calculator. I'd propose https://roi.fyi/loan/ as a modern, non-commercial reference (to answer the request below)... but it still doesn't serve a role that can't be handled by Amortization. Qwidjib0 (talk) 20:55, 29 January 2023 (UTC)

Seriously, someone add some examples to this completely dead article. Amortization is an already difficult to find subject on the internet... Writing an article with absolutely ZERO examples is idiotic and ultimately non-helpful. — Preceding unsigned comment added by 66.58.188.98 (talk) 03:15, 2 February 2014 (UTC)

How do we calculate based on a 365-day year? I believe that should be included in this article. —Preceding unsigned comment added by 216.114.198.130 (talk) 16:12, 15 December 2008 (UTC)

The first equation in the article shows an equivalent form. I tried it with that form and it doesn't work. I suspect the equivalent form has an error. Tried it for yourself. —Preceding unsigned comment added by 70.90.46.81 (talk) 17:13, 12 October 2008 (UTC)

I do not have the confidence to edit this page but I suggest that the maths behind derivation of this formula be illustrated if possible. Also since there is a repeated term ,in the formula at the time of writing, can the author divide 'top and bottom' by this factor and simplify the equation so it only has to be used once ? Many thanks for the input from all of the contributers.

J_B. Is there an excel or openoffice (calc) tutorial where how to do mortgage calculations are explained ?

Is it possible to post excel spreadsheets on wikipedia? I wouldn't mind adding a sample amortization schedule.

I think this article should make the distinction clear between dealing with installment debt and revolving loans. Additionally, it should make explicit reference to concepts of APR and Truth-in-Lending regulations. I will begin to make these contributions. -- Mhervitz 14:59, 21 July 2006 (UTC)

Mhervitz, please do, as it seems strange to me that one would suggest it can also be used to analyze revolving loans (e.g. credit cards). It is a fine estimate but it is not completely accurate and doesn't show how total interest paid changes with payment. E.g., by my calculations one can save just over $7.50 in interest (big deal, I guess, but accurate) on a $9000 balance over 12 months at 1.99% APR if one pays 826.31 over the amortization calculator's suggestion of 758.11 (final payment will be about $0.03 for the $826 payment... just one penny more and it would be an 11 month payoff--of course, this depends on when the payoff starts). (Erislover 19:16, 14 June 2007 (UTC))

Propose merge with time value of money
This is not a very standard term, and it also is a little confusing as written here. Merging would seem to be easier than fixing this page.--Gregalton 02:30, 11 February 2007 (UTC)

please, help me to stop this vandal.
This link: calculator-loan.info has been in the encyclopedia for 2 months since 7 of May 2007. The vandal 138.88.117.182 (138.88.169.147) came on 4 July 2007 and sneaky changed the link for his own. After I undid his change he keeps deleting the original link. Please, somebody help to stop him. Ivanups 06:17, 7 July 2007 (UTC)

Please provide a useful non commercial Website. Your site calculator-loan.info was littered with Google Ads and offered no value to the Wikipedia Community. I also noticed that you removed the ads after you posted this message. We consider that spamming here.

For 2 months it has not been spammy, but now you decide so. Why did you remove this link, the next one also has Google Ads? And speak only for yourself not for the whole community. That site (calculator-loan.info) has got average 5 pages per viewer, so people find that site useful since they use that calculator and it is not up to you to decide about of usefulness of this link. If you consider that you link has some value for this article, go ahead and add your link and let to the community decide is it valuable or not. And do not do like before when you just removed other link, please. Ivanups 18:20, 7 July 2007 (UTC)

I'll leave it up to the community then. I just think it's shady to remove all the ads on your site before calling me a vandal for removing your site and crying foul. Being listed there for two months isn't really a sound argument for being allowed to be there. Again, the community will decide so if you decide to spam again in the future I'm sure your site will receive the proper treatment. You can take it up then with the next so called "vandal."

Adding external links
I have again removed a number of links to websites that do not seem to meet Wikipedia guidelines for external links. It would be more helpful to discuss the value and notability of each individual link to the article rather than just trying to readd them enmass. Flowanda | Talk 01:11, 8 May 2008 (UTC)

HELP on How to Amortise Transaction Cost & Upfront Fee??
Hi,

This is my first post here and hope I didnt make any posting errors.

Can anyone guide me on the following: (A) I have a 15 year bank loan with 155 monthly principal repayment commencing from the 25th month and 1 lump sum final principal repayment at end of loan (B) When we draw down the loan, we paid transaction cost & upfront fee.

Can I know how to amortise the transaction cost & upfront fee to the respective loan period?

Many thanks Anson Tonykhkwan (talk) 02:55, 19 November 2008 (UTC)

Needs useful non commercial Website with a working amortization calculator
Might WolframAlpha's be OK? http://www.wolframalpha.com/input/?i=principal+and+interest

Might someone point to one or build one on Wiki commons?

Ideally, the calculations would be done on the host machine, so that it was not necessary to allow javascript or java access to the user's computer.

There is information on making a Java or a Excel calculator on eHow. However these pages appear to be blocked from Wikipedia.

java-amortization-calculator-code.html on eHow.

create-loan-amortization-table-excel.html on eHow.

More formulas
These are formulas that can be used for fixed rate/fixed payment calculations.


 * present value: v
 * future value: f
 * number of payments: k
 * interest rate: r
 * payment: p

(v*r^k-f)*(1-r)/(1-r^k) -> p

ln((f*r-p-f)/(v*r-p-v))/(ln(r)) -> k

((v*r-p-v)*r^k+p)/(r-1) -> f

I am just putting them here since I usually don't see the future value included, and I ended up deriving them myself. Jrincayc (talk) 14:47, 13 August 2010 (UTC)

Conceptual confusion over interest rate There is a disjuncture between the rate of interest used in the calculation and proof and the percentage rate of interest in the text.

To illustrate, an annual rate of interest of 8% is an annual percentage rate of 8, but the rate required by the proof and the rate which I suspect is required in these calculations is nothing like that at all.

It is in fact (100 +8)/100 = 1.08

Now that is merely junior high school arithmetic for most, but the article confuses the two. I will verify this by using the formula in a spreadsheet. Optymystic (talk) 13:24, 2 November 2011 (UTC)

Now I've checked I see that the text distinguishes between r the rate used in the proof and i the percentage rate of interest, but it still treats r as 1 +i because 1 + 8% is 1.08 and not 1 + 8% = 9%, which might not be obvious to some readers.

PS formulae verified in spreadsheet - they do work. Optymystic (talk) 00:07, 3 November 2011 (UTC)