How can you determine principal and interest rate of a loan given the term, monthly payment and first period interest? I did it the hard way by tabulating interest payments for a range of interest rates and principals then calculating principal for specific combinations.

For a 60 month loan with a monthly payment of $594.40 and first month interest component of $124.26, I got a principal of $31,700 and an interest rate of 4.75%. How can I confirm this is a unique solution through $50,000 and 15% other than increasing resolution in the table? Is there a solution I'm missing in the 7-8% range?

Thanks,
Sixto
87 300D

Google “loan calculator” or “amortization calculation” and find one that you put in what you know, and it fills in the rest.

Personally – I use a TI 84 Plus.

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1980 300D - Veggie Burner !

Do I see a new MB in your drive?

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1987 560SL
85,000 miles

http://teachertech.rice.edu/Participants/bchristo/lessons/carpaymt.html

I cheat and use google calculators.

Which MB are you buying?

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1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

Essentially you want to shoot for the biggest monthly payment you can safely afford to pay off the loan ASAP. That's probably the opposite of how most car buyers think, but it's the correct way if you want to save money in the long run. Even better, save up enough money to buy without borrowing.

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2004 VW Jetta TDI (manual)

Past MB's: '96 E300D, '83 240D, '82 300D, '87 300D, '87 420SEL

Awww, come on Med..... just punch the info in your HP 12B and give the man a break!

I use the 17BII and if you give them the answer they learn nothing.


Oh and its 12C Mr. Numbers man

Soo-ooo-rrr-yyy. Mine's the programmable "book" HP19B Bsns Consultant II. Got hung up on the letter B I guess. My bad.

Meant to ask: did you get the pm about the IRS & homebuyer credit fraud?

I have a 12C but I don't remember how to use it for this query.

No, I'm not getting a car. Someone asked if I was interested in taking over an existing loan. What I noted in the OP is all they could remember. They couldn't remember the rate or financed amount. Sounds like one of those 'how do I get out of this room' puzzles. I should be able to figure it out more quickly than using Excel.

Sixto
87 300D

Excel works pretty good.

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MB-less

Yes it does but I'm looking for an Excel function. I don't know how to solve this with Excel other than by building a table to eyeball the answer.

Sixto
87 300D

Check out: http://www.bloomberg.com/invest/calculators/autoloan.html

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1985 380SE Blue/Blue - 230,000 miles
2012 Subaru Forester 5-speed
2005 Toyota Sienna
2004 Chrysler Sebring convertible
1999 Toyota Tacoma

How is the battery door on your 19? mine is held together with yellow electrical tape I will post a picture today.

The update was just as you described last year and I forwarded to a few people who I am sure are not sleeping well.

No problem with the batt. door. To be honest, I use it mostly out of the office. We use TValue software in office calcs and schedules.

You mean people would actually try to cheat Uncle out of $8,000. I'm shocked. Shocked, I tell ya.
Maybe it's just in poor downtrodden Michigan.