help with how a loan repayment is calculated
"It appears the interest is not compounded daily.  Each period of interest has the loan amount calculated on the ""capital"" remaining on the start of period, for each day in the period.  The Excel finance functions don't handle irregular periods that well, but I can reconstruct the interest calculations:" In this case, it looks like the interest is simply the nominal daily interest rate times number of days in the period. From that you can use a spreadsheet to calculate the total payment by trial and error. With the different number of days in each period, any formula would be very complicated. In the more usual case where the interest charge for each period is the same, the formula is: m=P*r^n*(r-1)/(r^n-1) where * is multiplication ^ is exponentiation / is division (Sorry, don't know if there's a way to show formulas cleanly on here) P=original principle r=growth factor per payment period, i.e. interest rate + 100% divided by 100, e.g. 1% -> 1.01 n=number of payments Note the growth factor above is per period, so if you have monthly payments, it's the rate per month. The last payment may be different because of rounding errors, unequal number of days per period, or other technicalities. Using that formula here won't give the right answer because of the unequal periods, but it should be close. Let's see: r=0.7% times an average of 28.8 days per period gives 20.16% + 1 = 1.2016. n=5 P=500 m=500*1.2016^5*(1.2016-1)/(1.2016^5-1) =167.78 Further off than I expected, but ballpark.
To confirm: you say you have credit card debt of $18,000 with min. repayment of $466.06, plus on top of this you are also paying off a car loan and another personal loan. From my calculations if your monthly interest on your credit card is $237, the interest on your credit card should be about 15.8% p.a. Is this correct? Balance Transfer If you did a balance transfer of your $18,000 to a new credit card with 0% for 14 months and keep your repayments the same ($466) you would have saved yourself a bit over $3020 in interest over those 14 months. Your credit card balance after 14 months would be about $11,471 (instead of $14,476 with your current situation). If your interest after the 14 months went back to 15.8%  you would be able to pay the remaining $11,471 in 2.5 more years (keeping repayments at $466), saving 10 months off your repayments and a total of $4,781 in interest over 3 years and 8 months. The main emphasis here is that you are able to keep your repayments at least the same so you are able to pay off the debt quicker, and that your interest rate on the new credit card after the 14 months interest free is not more than your current interest rate of 15.8%. Things you should be careful about if you take this path: Debt Consolidation In regards to a Debt Consolidation for your personal loan and credit card (and possibly your car loan) into a single lower interest rate loan can be a good idea, but there are some pitfalls you should consider. Manly, if you are taking out a loan with a lower interest rate but a longer term to pay it off, you may end up paying less in monthly repayments but will end up paying more interest in the long run. If you do take this course of action try to keep your term to no longer than your current debt's terms, and try to keep your repayments as high as possible to pay the debt off as soon as possible and reduce any interest you have to pay. As you already have you credit card and personal loan with CBA talk to them to see what kind of deal they can give you. Again be wary of the fine print and read the PDS of any products you are thinking of getting. Refer to ASIC - Money Smart website for more valuable information you should consider before taking out any debt consolidation. Other Action You Can Take If you are finding that the repayments are really getting out of hand and no one will help you with any debt consolidation or reducing your interest rates on your debts, as a last resort you can apply for a Part 9 debt agreement. But be very careful as this is an alternative to bankruptcy, and like bankruptcy a debt agreement will appear on your credit file for seven years and your name will be listed on the National Personal Insolvency Index forever. Further Assistance and Help If you have trouble reading any PDS, or want further information or help regarding any issues I have raised or any other part of your financial situation you can contact Centrelink's Financial Information Service. They provide a free and confidential service that provides education and information on financial and lifestyle issues to all Australians. "So, there is no truly ""correct"" way to calculate return.  Professionals will often calculate many different rates of return depending on what they wish to understand about their portfolio.  However, the two most common ways of calculating multi-period return though are time-weighted return and money-weighted return. I'll leave the details to this good Investopeadia article, but the big picture is time-weighted returns help you understand how the stock performed during the period in question independent of how you invested it it.  Whereas money-weighted return helps you understand how you performed investing in the stock in question.  From your question, it appears both methods would be useful in combination to help you evaluate your portfolio. Both methods should be fairly easy to calculate yourself in a spread sheet, but if you are interested there are plenty of examples of both in google docs on the web." Am I eligible for the tax exemption if yes then under which section.  Generally Personal loans are not eligible for tax exemption. Only housing loans from qualified institutions are eligible for tax deduction. As per the income tax act; The house should be in your name. The home loans taken from recognised institutions are fully qualified under section 24B and 80C. This means you can claim Interest exemption under 24B and Principal repayment under 80C. The Act also specifies that loan can be taken from friends/relatives for construction of property and will be eligible for Interest exemption under 24B only. The principal will not be eligible for exemption under 80C. Read the FAQ from Income Tax India. There has to be certificate showing how much interest was paid on the said loan. Further there should be records/receipts on how the money was spent. There is difference of opinion amongst CA. It is best you take a professional advise. "Bankruptcy should be your last option, and you will find that BK will not resolve most of your problems, and create many more problems. There are two kinds of BK that are available to the average person, Ch13 debt repayment and Ch7 liquidation.  Both have severe repercussions and lasting effects on your credit (7-10 years, after discharge). And the calculations required under the 2005 BAPCPA are complex and may require help to understand. Ch7 liquidation is the more severe course, and the trustee would liquidate assets that exceed exemptions (vary by state) to pay your creditors. Ch13 debt repayment is hard, and only 20-25% of those who pursue that route complete the debt repayment plan.  Your credit score for either course would suffer greatly (200-250 points) and would remain reduced for years, especially since you would have to rebuild credit. And the law is flawed both in design and execution as there is no reward for successful debt repayment, few finish their repayment plan (20-25%), the mean recovery for unsecured creditors in repayment is zero (thus does not help creditors), and leaves the debtor with damaged credit for years (not a fresh start). Although you may have made some decisions that have placed you in a difficult position, you can find solutions to resolve these problems. You may find that simply learning to make better choices will improve your situation. Take a financial education course (such as the Dave Ramsey course), and learn how to budget, and make better choices. The LearnVest website offers a simple way to budget by dividing budgeting into only three (3) categories with suggested percentages for each, essentials (<50%), financial priorities (>20%), and lifestyle (<30%). The damage to your credit from the derogatory effects of BK would linger for years, but the damage from poor payment history declines much quicker, and loses most of the effect after 2 years (and should you keep the accounts open, leaves you with good history and longer account history), thus the effects decline to minimal after as little as 2 years of good behavior/payment history. Make a plan that prioritizes the debts, and how you will resolve the problem, and work the plan.  Based upon the income and debts you mention, the situation you have may not be as bad as it appears. You may be getting bad advice, especially from a debt settlement company that might be more interested in their fees than in your problem. Since you ""want to play fair and continue with payments, but when people start to get greedy like this I am ready to just stop caring"", you really need two things, a plan, and a friend, someone who you can talk to honestly and openly, and who can support you as you work through the plan you make. Since you ""would prefer the option that will give me the most peace of mind and allow me to start saving money as soon as possible"", you need to find an approach that fits your goals.  Your statement that you ""don't plan on ever using credit again"", fits with the Dave Ramsey philosophy and resonates with many of us who have learned that those who grant credit are often harsh masters. Now that you have provided more information, the advice below expands upon the above reflecting upon your specific situation. Since you make $62K/year, you may be close to the median income, and the BAPCPA (Bankruptcy Abuse Prevention and Consumer Protection Act of 2005) has a presumption of abuse for filing Ch7 when you have above median income (for your state, check the law). As you may be pushed into Ch13 debt repayment anyway, examine what you could do to repay the debt (over 5 years, 60 months, as that would be a Ch13 repayment duration). Since you have $8K of revolving (unsecured?) debt, that would be repaid in Ch13 over 60 months at about $133/month (no interest), but you would also be paying 10% to the trustee.  There might be some portion of your auto debt which is unsecured, and also be repaid unsecured, suppose that is $3000.  That would add another $50/month to the plan. The car could be repaid over 60 months (including interest), so you might be repaying $300/month for the car (estimate), although the payment could be higher or lower depending upon how much of the value of the car is unsecured.  The trustee might object that the car is too expensive (depends upon the value, and the trustee), and require be liquidated. Since BK excludes relief for student loans, you might find yourself paying the student loans at the same payment. Your $62K income suggests that you have about $4200/month (guess, after taxes).  The mortgage payment is higher than 25% ($1050-1100 would be ideal for your income).  But after your mortgage payment you should still have about $3900.  Even with $300 for credit card debt, $500 for car, and $400 for student loans (guessing), that leaves $2700 for essentials (utilities, food), lifestyle (cellphone, entertainment), and savings. You might find a friend who is good at budgeting who would be willing to help you craft a budget and be your ""responsibility partner"" to help you stick to the budget. Here is a sample plan (your mileage may vary), Essentials (50%, $2100): $2180 Financial (30%, 1230): $1250 Lifestyle (20%, 840): $500 (pick up slack here, as you have high debt load)" First, assuming you are making payments for a savings deposit.  The present value of the deposit is the sum of the all the payments discounted to present value.  In this case they would be discounted by the rate of inflation: £100 deposited next year is worth less than £100 today because it will be eroded by inflation.  With a higher rate of inflation the payments are discounted more heavily, so the present value decreases.  A deposit, or annuity due (see Calculating the Present Value of an Annuity Due), can be expressed mathematically like so:-  ∴ by induction  So for example, the following annuity has a present value of £1,136.76 The total amount that will be paid for the annuity is 12 x £100 = £1,200.  With a higher rate of inflation, say 2% per month, and with the same 12 x £100 payments, the present value of the annuity decreases. In Excel (£1,078.68) A similar case is that for a loan, or ordinary annuity (see Calculating the Present Value of an Ordinary Annuity), except the discounting factor is the loan interest rate rather than inflation and repayments are made at the end of each period rather than at the start. The present value of a loan is the value of the all the future repayments discounted to present value.  With a higher interest rate the payments are discounted more heavily, so the present value decreases.  A loan can be expressed mathematically like so:-  ∴ by induction  So for example, the following values fulfill a loan worth £1,125.51 The total amount that will be paid for the loan is 12 x £100 = £1,200.  With a higher rate of interest, say 2% per month, and the same 12 x £100 repayments, the present value of the loan that can be obtained decreases. In Excel (£1,057.53) The periodic rate (here, the interest charged per month), as you would enter into a finance calculator is 9.05%. Multiply by 12 to get 108.6% or calculate APR at 182.8%. Either way it's far more than 68%.  If the $1680 were paid after 365 days, it would be simple interest of 68%. For the fact that payment are made along the way, the numbers change.  Edit - A finance calculator has 5 buttons to cover the calculations:  N = number of periods or payments %i = the interest per period PV = present value PMT = Payment per period FV= Future value In your example, you've given us the number of periods, 12, present value, $1000, future value, 0, and payment, $140. The calculator tells me this is a monthly rate of 9%. As Dilip noted, you can compound as you wish, depending on what you are looking for, but the 9% isn't an opinion, it's the math. TI BA-35 Solar. Discontinued, but available on eBay. Worth every cent.  Per mhoran's comment, I'll add the spreadsheet version.  I literally copied and pasted his text into a open cell, and after entering the cell shows,  which I rounded to 9.05%. Note, the $1000 is negative, it starts as an amount owed.  And for Dilip - 1.0905^12 = 2.8281 or 182.8% effective rate. If I am the loanshark lending this money, charging 9% per month, my $1000 investment returns $2828 by the end of the year, assuming, of course, that the payment is reinvested immediately. The 108 >> 182 seems disturbing, but for lower numbers, even 12% per year, the monthly compounding only results in 12.68% "Trying to figure out how much money you have available each day sounds like you're making this more complicated than it needs to be. Unless you're extremely tight and you're trying to squeeze by day by day, asking ""do I have enough cash to buy food for today?"" and so on, you're doing too much work. Here's what I do. I make a list of all my bills. Some are a fixed amount every month, like the mortgage and insurance premiums. Others are variable, like electric and heating bills, but still pretty predictable.  Most bills are monthly, but I have a few that come less frequently, like water bills in my area come every 3 months and I have to pay property taxes twice a year. For these you have to calculate how much they cost each month. Like for the water bill, it's once every 3 months so I divide a typical bill by 3. Always round up or estimate a little high to be safe. Groceries are a little tricky because I don't buy groceries on any regular schedule, and sometimes I buy a whole bunch at once and other times just a few things. When groceries were a bigger share of my income, I kept track of what I spent for a couple of months to figure out an average per month. (Today I'm a little richer and I just think of groceries as coming from my spending money.) I allocate a percentage of my income for contributions to church and charities and count this just like bills. It's a good idea to put aside something for savings and/or paying down any outstanding loans every month. Then I add these up to say okay, here's how much I need each month to pay the bills. Subtract that from my monthly income and that's what I have for spending money. I get paid twice a month so I generally pay bills when I get paid. For most bills the due date is far enough ahead that I can wait the maximum half a month to pay it. (Worst case the bill comes the day after I pay the bills from this paycheck.)  Then I keep enough money in my checking account to, (a) Cover any bills until the next paycheck and allow for the particularly large bills; and (b) provide some cushion in case I make a mistake -- forget to record a check or make an arithmetic error or whatever; and (c) provide some cushion for short-term unexpected expenses. To be safe, (a) should be the total of your bills for a month, or as close to that as you can manage. (b) should be a couple of hundred dollars if you can manage it, more if you make a lot of mistakes. If you've calculated your expenses properly and only spend the difference, keeping enough money in the bank should fall out naturally. I think it's a lot easier to try to manage your money on a monthly basis than on a daily basis. Most of us don't spend money every day, and we spend wildly different amounts from day to day. Most days I probably spend zero, but then one day I'll buy a new TV or computer and spend hundreds.  Update in response to question What I do in real life is this: To calculate my available cash to spend, I simply take the balance in my checking account -- assuming that all checks and electronic payments have cleared. My mortgage is deducted from my checking every month so I post that to my checking a month in advance. I pay a lot of things with automatic charges to a credit card these days, so my credit card bills are large and can't be ignored. So subtract my credit card balances. Subtract my reserve amount. What's left is how much I can afford to spend. So for example: Say I look at the balance in my checkbook today and it's, say, $3000. That's the balance after any checks and other transactions have cleared, and after subtracting my next mortgage payment. Then I subtract what I owe on credit cards. Let's say that was $1,200. So that leaves $1,800. I try to keep a reserve of $1,500. That's plenty to pay my routine monthly bills and leave a healthy reserve. So subtract another $1,500 leaves $300. That's how much I can spend. I could keep track of this with a spreadsheet or a database but what would that gain? The amount in my checking account is actual money. Any spreadsheet could accumulate errors and get farther and farther from accurate values. I use a spreadsheet to figure out how much spending money I should have each month, but that's just to use as a guideline. If it came to, say, $100, I wouldn't make grandiose plans about buying a new Mercedes. If it came to $5,000 a month than buying a fancy new car might be realistic. It also tells me how much I can spend without having to carefully check balances and add it up. These days I have a fair amount of spending money so when, for example, I recently decided I wanted to buy some software that cost $100 I just bought it with barely a second thought. When my spending money was more like $100 a month, lunch at a fast food place was a big event that I planned weeks in advance. (Obviously, I hope, don't get stupid about ""small amounts"". If you can easily afford $100 for an impulse purchase, that doesn't mean that you can afford $100 five times a day every day.) Two caveats: 1. It helps to have a limited number of credit cards so you can keep the balances under control. I have two credit cards I use for almost everything, so I only have two balances to keep track of. I used to have more and it got confusing, it was easy to lose track of how much I really owed, which is a set up for getting in trouble." If you know the amounts that were combined ($5,000 and $7,500 in your example) -- NOT the original loan amounts necessarily -- then you can calculate a payment schedule (in Excel, Google Sheets, online, etc.) using that amount and the interest rate.  You can then apply your payments ($100) to that payment schedule, making sure to either accrue interest if your $100 didn't cover the monthly payment, or pay down extra principal if your $100 more than covered the payment.   The outstanding principal is the amount left or remaining balance. A program like GnuCash or Quicken makes doing the payment schedule, and applying payments relatively easy to handle.  Spreadsheets will require you to have 36 lines (3 years x 12 months) of payment and recalculation detail, but that shouldn't be too much work. To be fair to your mother, make sure you include any partially accrued interest on the full balance when paying it off.  Or even better, include a full month's interest in the pay-off amount.