How to accurately calculate Apple's EPS
On closer look, it appears that Google Finance relies on the last released 10-k statement (filing date 10/30/2013), but outstanding shares as of last 10-Q statement. Using these forms, you get ($37,037M / 5.989B ) = $6.18 EPS. I think this is good to note, as you can manually calculate a more up to date EPS value than what the majority of investors out there are relying on.
"You'd have to check the terms of your contract. On most installment loans, I think, they calculate interest monthly, not daily. That is, if you make 3 payments of $96 over the course of the month instead of one payment of $288 at the end of the month (but before the due date), it makes absolutely zero difference to their interest calculation. They just total up your payments for the month. That's how my mortgage works and how some past loans I've had worked. All you'd accomplish is to cost yourself some time, postage if you're mailing payments, and waste the bank's time processing multiple payments. If the loan allows you to make pre-payments -- which I think most loans today do -- then what DOES work is to make an extra payment or an overpayment. If you have a few hundred extra dollars, make an extra payment. This reduces your principle and reduces the amount of interest you pay every month for the remainder of the loan. And if you're paying $1 less in interest, then that extra dollar goes against principle, which further reduces the amount you pay in interest the next month. This snowballs and can save you a lot in the long run. Better still, instead of paying $288 each month, pay, say, $300. Then every month you're nibbling away at the principle faster and faster. For example, I calculate that if you're paying $288 per month, you'll pay the loan off in 72 months and pay a total of $6062 in interest. Pay $300 per month and you'll pay it off in 67 months with a total of $6031 interest. Okay, not a huge deal. Pay $350 per month and you pay it off in 55 months with $5449 interest. (I just did quick calculations with a spreadsheet, not accurate to the penny, but close enough for comparison.) PS This is different from ""revolving credit"", like credit cards, where interest is calculated on the ""average daily balance"". With a credit card, making multiple payments would indeed reduce your interest. But not by much. If you pay $100 every 10 days instead of $300 at the end, then you're saving the interest on 20 days x $100 + 10 days x $100, so 12.5% = 0.03% per day, so 0.03% x ($2000+$1000) = 90 cents. If you're mailing your payments, the postage is 49 cents x 2 extra payments = 98 cents. You're losing 8 cents per month by doing this." "Actually, the other answer isn't strictly correct.  It's an estimate, giving a lower bound that gets less accurate as income increases.  Consider: U.S. income tax is based on a progressive tax system where there are income bracket levels with increasing tax rates. Example: Given U.S. 2009 federal tax rates for an individual filing as ""single"": Imagine somebody making $100000.  Assuming no other credits, deductions, or taxes, then income tax based on the above brackets & rates would be calculated as follows: Meaning the average tax rate for the single individual earning $100,000 is 21.72%. However, a pre-tax deduction from that income actually comes off at the top marginal tax rate.  Consider the same calculation but with taxable income reduced to $99,000 instead (i.e. simulating a pre-tax $1000 deduction): That's a difference of $280, which is more than the $217.20 savings that would have been estimated if just using the average tax rate method. Consequently, when trying to determine how much money would be saved by a tax deduction, it makes better sense to estimate using the marginal tax rate, which in this case was 28%.  It gets a little trickier if the deduction crosses a bracket boundary.  (Left as an exercise to the reader :-) Finally, in the case of the deduction being discussed, it also looks like payroll FICA taxes paid by the employee (Social Security's 6.2%, and Medicare's 1.45%) would be avoided as well; so add that to the marginal tax rate savings. The surest way to know how much would be saved, though, would be to do one's income tax return calculation without the deduction, and then with, and compare the numbers.  Tax software can make this very easy to do." The short answer is you'd be much better off paying up front in this case.  The present value of $2,500 plus 12 $500 monthly payments is $8,128 at a 12% discount rate, which is much higher then the $6,000 you could pay now. The long answer is how you get that present value.  How can I use time value of money to find the present value of money if I choose to go with option A? First of all, I'd question your discount rate.  A 12% discount rate means that you can safely reinvest the money that you're not spending today at a 12% annual (1% monthly) rate, which seems very high.  Normally for short-term spending decisions you'd use a risk-free rate, which would be closer to 1%-2%. However, to discount at 1% monthly you'd just divide each monthly payment by 1 plus the discount rate raised to the power of the number of periods until each payment. So the total is which is $8,127.54 You could also use the NPV function in Excel. It seems like to get an accurate answer the calculation of the interest rate should take into account compounding period as well? Correct, and in the example above the compounding is assumed to be monthly since that's the periodicity of the cash flows. You could calculate it with a different compounding period but it gets much more complicated and probably wouldn't make a significant difference. The discount rate does take compounding into effect, meaning if you saved the $5,628 (the PV of $8,128 minus the $2,500 initial payment), you'd earn 1% interest on $5,628 the first month, $5,128 plus that interest the second month, etc. The GuruFocus Link is just reporting the high and low price of the quarter.  Price Range (Average) – The estimated trade prices. The average price   is calculated from the time weighted average during the period. If no   price range is shown, the trade prices are estimated trade prices,   which are more accurate estimates. AAPL: $420.05 - $549.03 ($467.26) The numbers for the high and low match what I found for AAPL on Yahoo Finance. Keep in mind their definition uses estimate 3 times. "The mathematics site, WolframAlpha, provides such data. Here is a link to historic p/e data for Apple. You can chart other companies simply by typing ""p/e code"" into the search box.  For example, ""p/e XOM"" will give you historic p/e data for Exxon. A drop-down list box allows you to select a reporting period : 2 years, 5 years, 10 years, all data.  Below the chart you can read the minimum, maximum, and average p/e for the reporting period in addition to the dates on which the minimum and maximum were applicable." "(Value of shares+Dividends received)/(Initial investment) would be the typical formula though this is more of a percentage where 1 would indicate that you broke even, assuming no inflation to be factored. No, you don't have to estimate the share price based on revenues as I would question how well did anyone estimate what kind of revenues Facebook, Apple, or Google have had and will have. To estimate the value of shares, I'd likely consider what does my investment strategy use as metrics: Is it discounted cash flow, is it based on earnings, is it something else? There are many ways to determine what a stock ""should be worth"" that depending on what you want to believe there are more than a few ways one could go." Some other answers mention the ability to sell at grant. This is very important. If you have that ability, think about your guaranteed return. In my case, I get a 15% discount on the lowest 6 month window price from the last two years.  If you do the math, the worst case return can be calculated: 1) Money that from the beginning of the window, I make 15% for 6 months (30% annual return guaranteed) 2) Money at the end of the window (say the last month) is 15% for one month (180% annual return guaranteed) In the end, your average holding window for your money is about 3 months (you can calculate it exactly). At that rate, you have a guaranteed 60% annual return. You can't beat that anywhere, with a significant upside if your company stock is increasing. So, if your company has an instant sell at grant option, you have to be brain dead not to do it. If it takes time to get your shares, then you need to look at the volatility of the stock to see how big the chance of losing money is. To generalize to a formula (if that's what you want): WM = purchase window (in months); D = Discount Percentage; GR = Guaranteed Return GR = 12/(WM/2) * D = 6*D/WM One last thing, If you are going to participate in ESPP, make you that you understand how to do your taxes yourself. I haven't found a tax person yet who does ESPP correctly (including an ex IRS agent), so I always have to do my taxes myself to make sure they get done correctly. It costs them more to make the screens with more pixels. Let's say I usually pay you 10$ for something that cost you 5$ to make. Now I pay you 20$ for something that costs you 18$ to make.  Sure you get 20$ instead of 10$, but your profit per item went from 5$ down to 2$. Same thing here, the screens with 4x the pixels costs much more than the original screens. Apple paid slightly more for them, but not enough to keep the profit margin.