By William Turner (Wturner) on Thursday, December 13, 2001 - 03:40 pm: Edit

I am trying to figure out the formula for determining the payout/principal for a car loan given the APR, number of months, times compounded per year, ect.

I think it almost looks similar to this...
P=Principal
.1075=APR (sucks, I know)

[P+(.1075P/365)*????]/48(months)=monthly payment

But, I know my monthly payment, I want to figure my principal every month after I make the payment.

Does anyone know the equation I am looking for???

By Ron Ward (Ronward) on Thursday, December 13, 2001 - 03:48 pm: Edit

William,

Give me the principal (loan) amount and it can be calculated easily on my 12C for both prin and int amounts.

Ron Ward

By William Turner (Wturner) on Thursday, December 13, 2001 - 04:07 pm: Edit

Pay off as of today is $15,014.47 Next(9th) payment of $443.09 is due 12/21.

I have a 4 year loan so a total of 48 pmts. 40 more if I drag it out.

I can always call the bank and get the amount, I just would like the equation so I could do it whenever.

By KJ on Thursday, December 13, 2001 - 04:08 pm: Edit

William,

You are looking for an amortization schedule. Go to edmunds.com or fool.com and look for the links to their calculators. You should be able to print it out once you plug in all the details.

Karen

By William Turner (Wturner) on Thursday, December 13, 2001 - 04:08 pm: Edit

Initial principal was $17218.05

By William Turner (Wturner) on Thursday, December 13, 2001 - 04:26 pm: Edit

Karen,

I went there and they didn't have the info I was looking for.

Thanks anyway

By Kent Westbrook on Thursday, December 13, 2001 - 04:57 pm: Edit

William,

I quit using formulas in college, work with a calculator now. You're in school, right? Don't they let you use financial calculators? Or do your teachers want you to learn it the old fashioned way? I could probably figure out a way to run you an amort. schedule on Excel if you're interested, could e-mail to you. Let me know.

Kent

By William Turner (Wturner) on Thursday, December 13, 2001 - 05:30 pm: Edit

Kent,

Yes I am in school, but this is for my own amusment. I am a weirdo about this sort of thing. I don't have a finance calc nor will I probably ever get one (ME major, not finance).

The program in excel would be real cool.

My e-mail at work (where I have excel) is [email protected]

Thanks

By Mike Rupp (Mike_Rupp) on Thursday, December 13, 2001 - 06:51 pm: Edit

William:

Use the =pv formula in Excel. Go to help to get the details.

Mike
Finance Major '91

By charlie on Thursday, December 13, 2001 - 07:02 pm: Edit

Try to use =PMT on excel if you are trying to figure out the payment.

HP12C rules!!!

---Charlie

By Ron on Thursday, December 13, 2001 - 07:04 pm: Edit

17B

12c is for oldtimers

Ron

By charlie on Thursday, December 13, 2001 - 07:13 pm: Edit

Can't believe I have just became the oldtimer at 28 years old.
I guess my prof. my peers, and my mentors(if any) are all old timers

By Ron on Thursday, December 13, 2001 - 07:15 pm: Edit

hehehehe

You should "upgrade" to what us young turks use. More features and easier to do complicated things too.

Ron

By charlie on Thursday, December 13, 2001 - 07:18 pm: Edit

At least I know 12C is CFA approved and 17b is not
12C still rules

By Ron on Thursday, December 13, 2001 - 07:24 pm: Edit

For the test you mean?

Ron

By charlie on Thursday, December 13, 2001 - 07:43 pm: Edit

yep

By Anonymous on Thursday, December 13, 2001 - 07:59 pm: Edit

from a 17 year old high schooler who's taken this in the past few years....
use the PERT formula where P = e^r * t
where e a constant
just my thoughts....

By Ron Ward (Ronward) on Thursday, December 13, 2001 - 08:21 pm: Edit

12C rules indeed. However, as I worked late this evening, AND my new shocks, steering damper and rear brake pads arrived today from RN, I ran out of the office in a hurry and left the 12C behind. You're on your own for the night, Bro.

Ron Ward

By Roverine on Thursday, December 13, 2001 - 08:45 pm: Edit

I've got 2 old 12C's! ... (does this mean I'm a double old timer?)

Kim
... it does when I can't think of how to calculate it right now ...

By KJ on Thursday, December 13, 2001 - 10:38 pm: Edit

William,

Try this link:

http://www.fool.com/calcs/calculators.htm#auto

After you plug in the numbers, click through the various screens and you'll get to a mort schedule at the end.

Karen

By KJ on Thursday, December 13, 2001 - 10:40 pm: Edit

P.S. Click on the link for "How much will my payments be", and go from there.

Karen

By Kent Westbrook on Thursday, December 13, 2001 - 11:35 pm: Edit

Geez Ron,

Guess I'm an oldtimer too. My 12C has served me well for damn near 20 years! In "calculator years" that would make it as ancient as your Noah!!

William,

Looks like others have given you some good hints since I last posted. But I'll see what I can come up with.

Kent

By Kyle Beckman (Kbeckman) on Thursday, December 13, 2001 - 11:49 pm: Edit

I had a 32S that got me through all of my Mech E classes. After college I loaned it to my sister, who promptly lost. This was 4 years ago, and she still hasn't replaced it! But I'm not holding a grudge.

Kyle

By Ron on Friday, December 14, 2001 - 12:48 am: Edit

Kent,

You up for the spacer install, I have some free time. Email me at the yahoo address if you want to give it a shot.

12C is allright just the 17B can do so much more that required extra steps with the 12C

Did not mean to offend the old timers

My father still has a slide rule if that makes you feel better.

Ron

By Glenn Guinto (Glenn) on Friday, December 14, 2001 - 10:16 am: Edit

William,

I work for a credit union so I had one of the loan folks figure it out for you. If you took this loan out today and your first payment date is the Dec 31st for 48 months, with a 10.75 APR, here is what it would look like:

For 2001:

Pmt	Payment	Payment	Interest	Principal	CDI	CLI	Balance
#	Date	Amount	Paid	Paid	Premium	Premium	Remaining
---	----------	---------	--------	---------	-------	-------	----------
1	12/31/01	441.14	86.21	354.93			16863.12
Year	End Totals	441.14	86.21	354.93	0	0

For 2002:

Pmt	Payment	Payment	Interest	Principal	CDI	CLI	Balance
#	Date	Amount	Paid	Paid	Premium	Premium	Remaining
---	----------	---------	--------	---------	-------	-------	----------
2	1/31/02	441.14	153.96	287.18			16575.94
3	2/28/02	441.14	136.69	304.45			16271.49
4	3/31/02	441.14	148.56	292.58			15978.91
5	4/30/02	441.14	141.18	299.96			15678.95
6	5/31/02	441.14	143.15	297.99			15380.96
7	6/30/02	441.14	135.9	305.24			15075.72
8	7/31/02	441.14	137.64	303.5			14772.22
9	8/31/02	441.14	134.87	306.27			14465.95
10	9/30/02	441.14	127.82	313.32			14152.63
11	10/31/02	441.14	129.22	311.92			13840.71
12	11/30/02	441.14	122.29	318.85			13521.86
13	12/31/02	441.14	123.46	317.68			13204.18
Year	End Totals	5293.68	1634.74	3658.94	0	0

For 2003:

Pmt	Payment	Payment	Interest	Principal	CDI	CLI	Balance
#	Date	Amount	Paid	Paid	Premium	Premium	Remaining
---	----------	---------	--------	---------	-------	-------	----------
14	1/31/03	441.14	120.56	320.58			12883.6
15	2/28/03	441.14	106.25	334.89			12548.71
16	3/31/03	441.14	114.57	326.57			12222.14
17	4/30/03	441.14	107.99	333.15			11888.99
18	5/31/03	441.14	108.55	332.59			11556.4
19	6/30/03	441.14	102.11	339.03			11217.37
20	7/31/03	441.14	102.42	338.72			10878.65
21	8/31/03	441.14	99.32	341.82			10536.83
22	9/30/03	441.14	93.1	348.04			10188.79
23	10/31/03	441.14	93.03	348.11			9840.68
24	11/30/03	441.14	86.95	354.19			9486.49
25	12/31/03	441.14	86.61	354.53			9131.96
Year	End Totals	5293.68	1221.46	4072.22	0	0

For 2004:

Pmt	Payment	Payment	Interest	Principal	CDI	CLI	Balance
#	Date	Amount	Paid	Paid	Premium	Premium	Remaining
---	----------	---------	--------	---------	-------	-------	----------
26	1/31/04	441.14	83.38	357.76			8774.2
27	2/29/04	441.14	74.94	366.2			8408
28	3/31/04	441.14	76.77	364.37			8043.63
29	4/30/04	441.14	71.07	370.07			7673.56
30	5/31/04	441.14	70.06	371.08			7302.48
31	6/30/04	441.14	64.52	376.62			6925.86
32	7/31/04	441.14	63.23	377.91			6547.95
33	8/31/04	441.14	59.78	381.36			6166.59
34	9/30/04	441.14	54.49	386.65			5779.94
35	10/31/04	441.14	52.77	388.37			5391.57
36	11/30/04	441.14	47.64	393.5			4998.07
37	12/31/04	441.14	45.63	395.51			4602.56
Year	End Totals	5293.68	764.28	4529.4	0	0

For 2005:

Pmt	Payment	Payment	Interest	Principal	CDI	CLI	Balance
#	Date	Amount	Paid	Paid	Premium	Premium	Remaining
---	----------	---------	--------	---------	-------	-------	----------
38	1/31/05	441.14	42.02	399.12			4203.44
39	2/28/05	441.14	34.66	406.48			3796.96
40	3/31/05	441.14	34.67	406.47			3390.49
41	4/30/05	441.14	29.96	411.18			2979.31
42	5/31/05	441.14	27.2	413.94			2565.37
43	6/30/05	441.14	22.67	418.47			2146.9
44	7/31/05	441.14	19.6	421.54			1725.36
45	8/31/05	441.14	15.75	425.39			1299.97
46	9/30/05	441.14	11.49	429.65			870.32
47	10/31/05	441.14	7.95	433.19			437.13
48	11/30/05	440.99	3.86	437.13			0
Year	End Totals	4852.39	249.83	4602.56	0	0

And the final tally is:

Pmt	Payment	Payment	Interest	Principal	CDI	CLI	Balance
#	Date	Amount	Paid	Paid	Premium	Premium	Remaining
---	----------	---------	--------	---------	-------	-------	----------
Grand	Total	21174.57	3956.52	17218.05

CDI stands for Credit Disability Insurance, should you get disabled, your loan gets paid and CLI stands for Credit Life Insurance, should you die, your loan gets paid. I know there's a difference on your payment versus the payment we calculated. You probably pay extra for a CDI or CLI. If you have any other questions, I'll try to answer them for you!

Glenn
-your friendly neighborhood lender

By William Turner (Wturner) on Friday, December 14, 2001 - 12:18 pm: Edit

I don't have either. The way I see it is the CDI, well that is a gamble on the fact that I am 21, and am more unlikely to get disabled.

The CLI, well if I am dead, then chances are I am not going to give a shit about that loan

By SOLO on Friday, December 14, 2001 - 01:08 pm: Edit

Now I know why I became a Business Management Major and not a Finance major....too many numbers.

Larry