Can I change my loan term from 60 to 36 months?
Some places banks/Credit Unions will allow you to refinance a auto loan. My credit Union only does this if the original loan was with another lender. They will send the money to the old lender, then give you a loan under the new terms. They are trying to get your business, not necessarily looking for a way make less money for themselves.  You will have to see how much you will save. Which will be based on the delta of the length of the loan or the change in interest rate, or both. My Credit Union has a calculator to show you the numbers based on keeping the size of the payments the same, or keeping the number of payments the same.  Make sure you understand any limitations regarding the refinance based on the age of the car, and if you are underwater. Just call your credit union and ask if they will let you refinance at the lower rate. If they won't, then just increase your payment every month so that your car is paid off early (in 36 months instead of 60). You won't get the lower rate, but since your loan will be paid early, you'll be saving interest anyway.
I am answering this in light of the OP mentioning the desire to buy a house.  A proper mortgage uses debt to income ratios. Typically 28/36 which means 28% of monthly gross can go toward PITI (principal, interest, tax, insurance) and the total debt can go as high as 36% including credit cards and car payment etc. So, if you earn $5000/mo (for easy math) the 8% gap (between 28 and 36) is $400. If you have zero debt, they don't let you use it for the mortgage, it's just ignored. So a low interest long term student loan should not be accelerated if you are planning to buy a house, better put that money to the down payment. But for credit cards, the $400/mo carries $8000 (banks treat it as though the payment is 5% of debt owed). So, I'd attack that debt with a vengeance.  No eating out, no movies, beer, etc. Pay it off as if your life depended on it, and you'll be happier in the long run. "By the sounds of things, you're not asking for a single formula but how to do the analysis... And for the record you're focusing on the wrong thing. You should be focusing on how much it costs to own your car during that time period, not your total equity.  Formulas:  I'm not sure how well you understand the nuts and bolts of the finance behind your question, (you may just be a pro and really want a consolidated equation to do this in one go.) So at the risk of over-specifying, I'll err on the side of starting at the very beginning. Any financial loan analysis is built on 5 items: (1) # of periods, (2) Present Value, (3) Future Value, (4) Payments, and (5) interest rate.  These are usually referred to in spreadsheet software as NPER, PV, FV, PMT, and Rate. Each one has its own Excel/google docs function where you can calculate one as a function of the other 4. I'll use those going forward and spare you the 'real math' equations.  Layout: If I were trying to solve your problem I would start by setting up the spreadsheet  up with column A as ""Period"". I would put this label in cell A2 and then starting from cell A3 as ""0"" and going to ""N"". 5 year loans will give you the highest purchase value w lowest payments, so n=60 months... but you also said 48 months so do whatever you want.  Then I would set up two tables side-by-side with 7 columns each. (Yes, seven.) Starting in C2, label the cells/columns as: ""Rate"", ""Car Value"", ""Loan Balance"", ""Payment"", ""Paid to Interest"", ""Principal"", and ""Accumulated Equity"". Then select and copy cells C2:I2 as the next set of column headers beginning in K2. (I usually skip a column to leave space because I'm OCD like that :) ) Numbers: Now you need to set up your initial set of numbers for each table. We'll do the older car in the left hand table and the newer one on the right. Let's say your rate is 5% APR. Put that in cell C1 (not C3). Then in cell C3 type =C$1/12. Car Value $12,000 in Cell D3. Then type ""Down Payment"" in cell E1 and put 10% in cell D1. And last, in cell E3 put the formula =D3*(1-D$1). This should leave you with a value for the first month in the Rate, Car Value, and Loan Balance columns. Now select C1:E3 and paste those to the right hand table. The only thing you will need to change is the ""Car Value"" to $20,000. As a check, you should have .0042 / 12,000 / 10,800 on the left and then .0042 / 20,000 / 18,000 on the right.  Formulas again: This is where spreadsheets become amazing. If we set up the right formulas, you can copy and paste them and do this very complicated analysis very quickly.  Payment The excel formula for Payment is =PMT(Rate, NPER, PV, FV). FV is usually zero. So in cell F3, type the formula =PMT(C3, 60, E3, 0). Obviously if you're really doing a 48 month (4 year) loan then you'll need to change the 60 to 48. You should be able to copy the result from cell F3 to N3 and the formula will update itself.  For the 60 months, I'm showing the 12K car/10.8K loan has a pmt of $203.81. The 20K/18K loan has a pmt of 339.68.  Interest The easiest way to calculate the interest is as =E3*C3. That's (Outstanding Loan Balance) x (Periodic Interest Rate). Put this in cell G4, since you don't actually owe any interest at Period 0.  Principal If you pay PMT each month and X goes to interest, then the amount to principal is ""PMT - X"". So in H4 type =-F3 - G3. The 'minus' in front of F3 is because excel's PMT function returns a negative amount. If you want to, feel free to type ""=-PMT(...)"" for the formula that's actually in F3. It's your call.  I get 159 for the amount to principal in period 1.  Accumulated Equity As I mentioned in the comment, your ""Equity"" comes from your initial Loan-to-Value and the accumulated principal payments. So the formula in this cell should reflect that. There are a variety of ways to do this... the easiest is just to compare your car's expected value to your loan balance every time. In cell I3, type =(D3-E3). That's your initial equity in the car before making any payments. Copy that cell and paste it to I4. You'll see it updates to =(D4-E3) automatically. (Right now that is zero... those cells are empty, but we're getting there) The important thing is that as JB King pointed out, your equity is a function of accumulated principal AND equity, which depreciates. This approach handles those both.  Finishing up the copy-and-paste formulas I know this is long, but we're almost done.  Rate // Period 1 In cell C4 type =C3.  Payment // Period 1 In cell F4 type =F3.  Loan Balance // Period 1 In cell E4 type =E3-H4. Your loan balance at the end of period is reduced by the principal you paid. I get 10,641.  Car Value // Period 1 This will vary depending on how you want to handle depreciation. If you ignore it, you're making a major error and it's not worth doing this entire analysis...  just buy the prettiest car and move on with life. But you also don't have to get it scientifically accurate. Go to someplace like edmunds.com and look up a ballpark. I'm using 4% depreciation per year for the old (12K) car and 7% for the newer car. However, I pulled those out of my ass so figure out what's a better ballpark.  In G1 type ""Depreciation"" and then put 4% in H1. In O1 type ""Depreciation"" and then 7% in P1. Now, in cell D4, put the formula =D3 * (1-(H$1/12)).  Paste formulas to flesh out table As a check, your row 4 should read 1 / .0042 / 11,960 / 10,641 / 203.81 / 45 / 159 / 1,319. If so, you're great. Copy cells C4:I4 and paste them into K4:Q4.  These will update to be .0042 / 19,883 / 17,735 / 339.68 / 75 / 265 / 2,148.  If you've got that, then copy C4:Q4 and paste it to C5:C63. You've built a full amortization table for your two hypothetical loans. Congratulations.  Making your decision I'm not going to tell you what to decide, but I'll give you a better idea of what to look at. I would personally make the decision based on total cost to own during that time period, plus a bit of ""x-factor"" for which car I really liked.  Look at Period 24, in columns I and Q. These are your 'equities' in each car. If you built the sheet using my made-up numbers, then you get ""Old Car Equity"" as 4,276. ""New Car Equity"" is 6,046. If you're only looking at most equity, you might make a poor financial decision.  The real value you should consider is the cost to own the car (not necessarily operate it) during that time... Total Cost = (Ending Equity) - (Payment x 24) - (Upfront Cash).  For your 'old' car, that's (4,276) - (203.81 * 24) - (1,200) = -1,815.75 For the 'new' car, that's (6,046) - (339.68 * 24) - (2,000) = -4,106.07.  Is one good or bad? Up to you to decide. There are excel formulas like ""CUMPRINC"" that can consolidate some of the table mechanics, but I assumed that if you're here asking you would have gotten stuck running some of those.  Here's the spreadsheet: https://docs.google.com/spreadsheet/ccc?key=0Ah0weE0QX65vdHpCNVpwUzlfYjlTY2VrNllXOS1CWUE#gid=1" What you put that money into is quite relevant. It depends on how soon you will need some, or all, of that money.  It has been very useful to me to divide my savings into three areas...  1) very short term 'oops' funds. This is for when you forget to put something in your budget or when a monthly bill is very high this month. Put this money into passbook savings.  2) Emergency funds that are needed quite infrequently. Used for such things as when you go to the hospital or an appliance breaks down. Put this money in higher yeald savings, but where it can be accessed.  3) Retirement savings. Put this money into a 401-K. Never draw on it till you retire. Make no loans against it. When you change jobs roll over into a self-directed IRA and invest in an ETF that pays dividends. Reinvest the dividend each month.  So, like I said, where you put that money depends on how soon you will need it. I faced something similar for travel or work reasons, and as for me I preferred wire transfer over credit card withdrawals because my bank has huge fees. My thoughts so far are: the fee can vary a lot for credit card. As for me, I can expect 5% fees on foreign withdrawals. But I considered changing bank and I think a Gold (or premium) card might be a good idea as well. The idea is you pay a big subscription (100 euros or so) but have no fee. The total of withdrawal fees could easily (if you stay long abroad) reach this amount. There are also banks like HSBC that offer low fees on withdrawals abroad, you can ask them. The problem is that you cannot really withdraw huge amounts to lower the fee (since you carry this cash in the street). for wire transfers the total fee is usually $50 or more (I had a fee from distant bank, a fee for change and a fee in my home bank). But the amount is unlimited (or high enough to be of little matter) and I needed to do this once per year or so. So I guess it could be interesting if you have enough savings to only transfer money every couple of months or so. I think Western Union is also involved this profitable business. I never used it because the fees are pretty high, but maybe it is useful for not too big amounts frequently transfered. Actually, have you considered a loan? It's a very random idea but maybe you can use a loan as a swap and then transfer money when you have enough to reimburse it all. But the question is very interesting, I think the business is pretty huge due to globalization. It is expensive because some people can make a lot of money out of it. That seems a very bad offer, it borders on fraud. In the current US economy, you should be able to get between 3 and 4 % APR (and that number is what you should look at). That means that for $300,000 over 30 years, you'd pay $1,265 to $1,432 per month. If you are able to pay more than that monthly rate, you should go for less than 30 years - 20, 15, 10, whatever you can afford - but don't overextend yourself. Google 'mortgage calculator' to do your own calculations. There are loan options for those in your situation.  It is very common.  I am a licensed loan officer nmls 1301324 and have done many loans just like this.  Your schooling is counted as your work history Contrary to popular belief.  We want to write loans and guidelines are easing.  Banks are a different story and their loan officers aren't licensed.  If you talk to a bank you aren't getting an educated loan officer.  They also have what are called overlays that make guidelines stricter. Yes, take the new rate, but instead of using the new 30 year term, calculate the payment as though the new mortgage were at the remaining term. 3 years into a 30? You calculate the payment as if the new mortgage were 27 years.  This will tell you what you are really saving. Now, take that savings and divide into your closing costs if any. That will give you the break even. Will you be in the house that long?  If you can find a no closing cost deal, it's worth it for even 1/8% savings. "There are some loan types where your minimum payment may be less than the interest due in the current period; this is not true of credit cards in the US.  Separately, if you have a minimum payment amount due of less than the interest due in the period, the net interest amount would just become principal anyway so differentiating it isn't meaningful. With credit cards in the US, the general minimum calculation is 1% of the principal outstanding plus all interest accrued in the period plus any fees.  Any overpayment is applied to the principal outstanding, because this is a revolving line of credit and unpaid interest or fees appear as a charge just like your coffee and also begin to accrue interest.  The issue arises if you have multiple interest rates.  Maybe you did a balance transfer at a discounted interest rate; does that balance get credited before the balance carried at the standard rate?  You'll have to call your lender.  While there is a regulation in place requiring payment to credit the highest rate balance first the banks still have latitude on how the payment is literally applied; explained below.   When there IS an amortization schedule, the issue is not ""principal or interest"" the issue is principle, or the next payment on the amortization schedule.  If the monthly payment on your car loan is $200, but you send $250, the bank will use the additional $50 to credit the next payment due.  When you get your statement next month (it's usually monthly) it will indicate an amount due of $150.  When you've prepaid more than an entire payment, the next payment is just farther in to the future.  You need to talk to your lender about ""unscheduled"" principal payments because the process will vary by lender and by specific loan. Call your lender.  You are a customer, you have a contract, they will explain this stuff to you.  There is no harm that can possibly come from learning the nuances of your agreement with them. Regarding the nuance to the payment regulation: A federal credit card reform law enacted in May 2009 requires that credit card companies must apply your entire payment, minus the required minimum payment amount, to the highest interest rate balance on your card.  Some credit card issuers are aggressive here and apply the non-interest portion of the minimum payment to the lowest interest rate first.  You'll need to call your bank and ask them."