# Can you calculate an answer to this question about a loan with interest? **URL:** \ **Category:** Factual Questions\ **Created:** [February 8, 2014, 2:40am UTC](https://boards.straightdope.com/t/can-you-calculate-an-answer-to-this-question-about-a-loan-with-interest/680810 "2014-02-08T02:40:04Z")\ **Posts on this page:** 6\ **Page:** 2
**Author:** ![Frylock](https://avatars.discourse-cdn.com/v4/letter/f/ce7236/32.png) [@Frylock](https://boards.straightdope.com/u/Frylock)\ **Post date:** [February 9, 2014, 2:25am UTC](https://boards.straightdope.com/t/can-you-calculate-an-answer-to-this-question-about-a-loan-with-interest/680810/21 "2014-02-09T02:25:07Z")
Lessee what’s going on here. Looking at the statement again, let me try to give the information as exactly as possible: Current Balance: 6,069.24 Last Payment Made\*: 281.11 Amount of Last Payment That Went to Principal: 261.65 Annual Percentage Rate: 3.400% “The balance used to compute interest is the unpaid balance each day after payments and credits to that balance have been subtracted and any additions ot the balance have been made.” Fees Charged: 0.00 Interest Charge: 19.46 Which is all what I said in the OP, I guess, but just repeating it here to show that I’ve gone back and double checked. Well, WTHeck could be happening, then? These numbers don’t add up somehow? \*i.e., the one after which the balance was 6069.24 ---
**Author:** ![Frylock](https://avatars.discourse-cdn.com/v4/letter/f/ce7236/32.png) [@Frylock](https://boards.straightdope.com/u/Frylock)\ **Post date:** [February 9, 2014, 2:29am UTC](https://boards.straightdope.com/t/can-you-calculate-an-answer-to-this-question-about-a-loan-with-interest/680810/22 "2014-02-09T02:29:22Z")
BTW in the OP when I said I was trying to figure out how much interest I “will pay over the life of the loan,” I meant over the remainder of the life of the loan. That may have confused some w.r.t. what my intentions were, so apologies for that. ---
**Author:** ![Baracus](https://avatars.discourse-cdn.com/v4/letter/b/2bfe46/32.png) [@Baracus](https://boards.straightdope.com/u/Baracus)\ **Post date:** [February 9, 2014, 2:36am UTC](https://boards.straightdope.com/t/can-you-calculate-an-answer-to-this-question-about-a-loan-with-interest/680810/23 "2014-02-09T02:36:56Z")
> [@Frylock](#): > > Lessee what’s going on here. > > Looking at the statement again, let me try to give the information as exactly as possible: > > Current Balance: 6,069.24 > > Last Payment Made\*: 281.11 > > Amount of Last Payment That Went to Principal: 261.65 > > Annual Percentage Rate: 3.400% > > “The balance used to compute interest is the unpaid balance each day after payments and credits to that balance have been subtracted and any additions ot the balance have been made.” > > Fees Charged: 0.00 > > Interest Charge: 19.46 > > Which is all what I said in the OP, I guess, but just repeating it here to show that I’ve gone back and double checked. > > Well, WTHeck could be happening, then? These numbers don’t add up somehow? > > \*i.e., the one after which the balance was 6069.24 I am guessing that everyone is assuming that the interest charged had accumulated over 30 or 31 days, but that for whatever reason it was actually more like 34 or 35. ---
**Author:** ![Topologist](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/topologist/32/3208_2.png) [@Topologist](https://boards.straightdope.com/u/Topologist)\ **Post date:** [February 9, 2014, 2:56am UTC](https://boards.straightdope.com/t/can-you-calculate-an-answer-to-this-question-about-a-loan-with-interest/680810/24 "2014-02-09T02:56:35Z")
> [@Frylock](#): > > Well, WTHeck could be happening, then? These numbers don’t add up somehow? Sorry, I must be doing something wrong, but I don’t see what it is. > [@Chronos](#): > > **Topologist** , one possible source of confusion is that the 3.4% figure isn’t the interest rate; it’s the APR. The APR basically takes into account compounding over the course of one year, while the interest rate doesn’t. Or to put it another way, an APR is a finite difference, while an interest rate is a derivative. > > I don’t think that actually resolves the confusion, though, since an APR will always be higher than an interest rate. Exactly, which is why I’m assuming that 3.4% is the nominal APR rather than the effective APR. If it were the effective rate, the problem would be worse, not better. > [@Baracus](#): > > I am guessing that everyone is assuming that the interest charged had accumulated over 30 or 31 days, but that for whatever reason it was actually more like 34 or 35. It might be 33 days if they’re using a 365-day year, but (a) I think most loans just divide the rate up 1/12 per monthly payment and (b) what month has 33 days? Would anyone in their right mind try to set up a loan with fixed payments over a long period of time and then calculate interest on the fly based on when the payments actually arrived? ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [February 9, 2014, 3:52am UTC](https://boards.straightdope.com/t/can-you-calculate-an-answer-to-this-question-about-a-loan-with-interest/680810/25 "2014-02-09T03:52:59Z")
Maybe the nominal date due is always a business day, and if it would fall on a weekend or holiday they bump it to Friday or something? That could maybe result in a 33-day “month”, I guess. ---
**Author:** ![excavating\_for\_a\_mind](https://avatars.discourse-cdn.com/v4/letter/e/e8c25b/32.png) [@excavating\_for\_a\_mind](https://boards.straightdope.com/u/excavating_for_a_mind)\ **Post date:** [February 9, 2014, 1:55pm UTC](https://boards.straightdope.com/t/can-you-calculate-an-answer-to-this-question-about-a-loan-with-interest/680810/26 "2014-02-09T13:55:21Z")
> [@Baracus](#): > > I am guessing that everyone is assuming that the interest charged had accumulated over 30 or 31 days, but that for whatever reason it was actually more like 34 or 35. I think this is it. The loan agreement probably has a “grace period” where the payment will be accepted after the “due date”. They would then calculate the amount of interest based on the actual date received. If the payment is due on the 1st, but they won’t charge “late fees” until the 15th, there could be quite a few extra days in there. We’d have to know when the due date was and when the payment was received. BTW, I think \*\* Tim R. Mortiss \*\*got it in post #8, paying the loan off now would save you a little over $200, a bit less than one payment. [Previous page](https://boards.straightdope.com/t/can-you-calculate-an-answer-to-this-question-about-a-loan-with-interest/680810.md?page=1)