How are mortgage payments decided? [duplicate]
It's easiest to get your payment from the PMT function in Excel or Google Sheets.  So a $100,000 30 year mortgage at 3% looks like this: The basic calculation is pretty simple.  You take the annual interest rate, say 3%, divided by 12, times the existing principal balance: The idea is that borrowers would like to have a predictable payment.  The earlier payments are proportionally more interest than principal than later payments are but that's because there is much more principal outstanding on month 1 than on month 200. It's so that your total mortgage payment stays the same every month. Obviously, the interest due each month decreases over time, as part of the principal is paid off each month, and so if the proportion of interest and principal repayments were to stay the same then your first payment would be very large and your last payment would be almost nothing. It has nothing to do with forcing people to pay off their debt; in that case it would make better sense to have people pay off debt rather than interest. It is because you want to have your actual payment stay the same each month, which is easier for the vast majority of people to comprehend and put into their budget. It is called an annuity in Finance terms. In theory you could use another method - eg. pay of the same amount of debt each month - then your interest payments will decrease over time. But in that case your monthly payment (debt + interest) will not be stable - It will start of high and decrease a little bit each month. With an annuity you have a constant cashflow. In Finance you generally operate with three methods of debt repayment: Annuity: Fixed cashflow. High interest payment in the beginning with small debt payments - later it will be reversed. Serial loan: Fixed debt payments. Debt payments are equally spread out accross the period - interst is paid on the remaining debt. Cash flow will decrease over time, because interest payments become smaller for each period. Standing loan: You only pay interest on the loan, no debt payments during the period. All debt is payed back in the end of the loan. In Europe it is common practise to combine a 30 year annuity with a 10 year standing loan, so that you only pay interest on the loan for the first 10 years, thereafter you start paying back the debt and interest, the fixed amount each month (the annuity). This is especially common for first-time buyers, since they usually have smaller salaries early in life than later and therefore need the additional free cash in the beginning of their adult life.
"Basically, the easiest way to do this is to chart out the ""what-ifs"". Applying the amortization formula (see here) using the numbers you supplied and a little guesswork, I calculated an interest rate of 3.75% (which is good) and that you've already made 17 semi-monthly payments (8 and a half months' worth) of $680.04, out of a 30-year, 720-payment loan term. These are the numbers I will use. Let's now suppose that tomorrow, you found $100 extra every two weeks in your budget, and decided to put it toward your mortgage starting with the next payment. That makes the semi-monthly payments $780 each. You would pay off the mortgage in 23 years (making 557 more payments instead of 703 more). Your total payments will be $434,460, down from $478.040, so your interest costs on the loan were reduced by $43,580 (but, my mistake, we can't count this amount as money in the bank; it's included in the next amount of money to come in). Now, after the mortgage is paid off, you have $780 semi-monthly for the remaining 73 months of your original 30-year loan (a total of $113,880) which you can now do something else with. If you stuffed it in your mattress, you'd earn 0% and so that's the worst-case scenario. For anything else to be worth it, you must be getting a rate of return such that $100 payments, 24 times a year for a total of 703 payments must equal $113,880. We use the future value annuity formula (here): v = p*((i+1)n-1)/i, plugging in v ($113880, our FV goal), $100 for P (the monthly payment) and 703 for n (total number of payments. We're looking for i, the interest rate. We're making 24 payments per year, so the value of i we find will be 1/24 of the stated annual interest rate of any account you put it into. We find that in order to make the same amount of money on an annuity that you save by paying off the loan, the interest rate on the account must average 3.07%. However, you're probably not going to stuff the savings from the mortgage in your mattress and sleep on it for 6 years. What if you invest it, in the same security you're considering now? That would be 146 payments of $780 into an interest-bearing account, plus the interest savings. Now, the interest rate on the security must be greater, because you're not only saving money on the mortgage, you're making money on the savings. Assuming the annuity APR stays the same now vs later, we find that the APR on the annuity must equal, surprise, 3.75% in order to end up with the same amount of money. Why is that? Well, the interest growing on your $100 semi-monthly exactly offsets the interest you would save on the mortgage by reducing the principal by $100. Both the loan balance you would remove and the annuity balance you increase would accrue the same interest over the same time if they had the same rate. The main difference, to you, is that by paying into the annuity now, you have cash now; by paying into the mortgage now, you don't have money now, but you have WAY more money later. The actual real time-values of the money, however, are the same; the future value of $200/mo for 30 years is equal to $0/mo for 24 years and then $1560/mo for 6 years, but the real money paid in over 30 years is $72,000 vs $112,320. That kind of math is why analysts encourage people to start retirement saving early. One more thing. If you live in the United States, the interest charges on your mortgage are tax-deductible. So, that $43,580 you saved by paying down the mortgage? Take 25% of it and throw it away as taxes (assuming you're in the most common wage-earner tax bracket). That's $10895 in potential tax savings that you don't get over the life of the loan. If you penalize the ""pay-off-early"" track by subtracting those extra taxes, you find that the break-even APR on the annuity account is about 3.095%." "I'm going to answer your questions out of order. Emergency fund: Depending on how conservative you are and how much insurance you have, you may want anywhere from 3-12 months of your expenses on hand. I like to keep 6 months worth liquid in a ""high-yield"" savings account. For your current expenses that would be $24k, but when this transaction completes, you will have a mortgage payment (which usually includes home-owners insurance and property taxes in addition to your other expenses) so a conservative guess might be an additional $3k/month, or a total of $42k for six months of expenses. So $40-$100k for an emergency fund depending on how conservative you are personally. Down payment: You should pay no less than 20% down ($150k) on a loan that size, particularly since you can afford it. My own philosophy is to pay as much as I can and pay the loan off as soon as possible, but there are valid reasons not to do that. If you can get a higher rate of return from that money invested elsewhere you may wish to keep a mortgage longer and invest the other money elsewhere. Mortgage term: A 15-year loan will generally get you the best interest rate available. If you paid $400k down, financing $350k at a 3.5% rate, your payment would be about $2500 on a 15-year loan. That doesn't include property taxes and home-owners insurance, but without knowing precisely where you live, I have no idea whether those would keep you inside the $3000 of additional monthly home expenses I mentioned above when discussing the emergency fund. That's how I would divide it up. I'd also pay more than the $2500 toward the mortgage if I could afford to, though I've always made that decision on a monthly basis when drawing up the budget for the next month." I'd put the 20% down, close on the house, live in it for a year, and save the difference.  If you find your cash flow is fine, run a calculation and start on a program of prepaying a bit of principal each month as an extra payment. If you study how amortization works, you'll understand that an extra payment of about 1/6 the amount due will knock off a full payment at the end. This is how a 30 year mortgage starts out. Meanwhile, you should keep in mind, it's easy to prepay the mortgage, but there's really no getting it back. So, before letting go of your money, I'd do a few things; I may be stating the obvious, but consider - No matter how low the payment on your mortgage, a payment is due each and every month until it's paid off. You put 80% down, take a 10 year mortgage, you still have payments for 10 years. You want to insure yourself against needing to sell in a hurry if you both lose your jobs, so whatever you put down, I'd recommend a healthy emergency account, 9-12 months worth of expenses. With the calculator in hand (Excel :) you should follow this advise and save a bundle. 1) Calculate how much you are willing to spend per month. 2) Take the longest (in years) mortgage you can find and cheepest (Euribor+0,2% is better than Euribor+1%). 3) Save the amount you are not spending on your mortgage. Whenever the mortgage cost changes (once a year), calculate whether you get more interests on your savings or on a down payment (look at the total cost). Then decide if you make a down payment or keep on saving. My 0,02€ We took a 20 year mortgage and blindly payed every time we'd have 3K€. We payed our house in 6 years. The total cost of the mortgage was way down this way. However, the above theory has a better yield overall. You would need to check the original mortgage papers you signed with the originators.  Chances are you agreed to allow the mortgage to be sold and serviced by other parties. Refinancing would also put you in the same boat unless you got them to take that clause out of the mortgage/refinance papers. Also, chances are most small banks and originators simply can not keep mortgages on their books. There are also third parties that service loans too that do not actually own the mortgages as well. This is another party that could be involved out of many in your mortgage.  I would also not worry about 127/139 complaints out of 1,100,000 loans. Most probably were underwater on their mortgage but I am sure a few are legitimate complaints.  Banks make mistakes (I know right!).  Anyway, good luck and let me know if you find out anything different. There are probably specific laws that control landlord/tenant rent disputes. But your friend's argument assumes that there aren't. Let's assume that there aren't. So there are two possibilities. Either the contract directly addresses this issue or it doesn't. If the contract directly and specifically addresses this issue, then that controls. Your friend is not claiming that it is specifically addressed. So the general principle is this -- when something occurs within a contract that wasn't explicitly discussed by the parties, courts will try to figure out what the parties likely would have agreed to had they discussed the specific issue (without changing the agreed terms of the contract). This should produce the result that is fair to both parties. Your friend is arguing then that had he and the landlord discussed the issue, the landlord would have agreed that in the event he is no longer able to accept credit cards easily, your friend could live there rent free. That doesn't seem right to me. Does it seem right to you? Much more likely they would have agreed that he might have some leeway to work out a new payment scheme and maybe some late rent should be forgiven if he made an attempt to pay on time but couldn't make arrangements. But I don't see more than that being reasonable. "We’re buying the home right over $200,000 so that means he will only need to put down (as a ‘gift’) roughly $7000. I'm with the others, don't call this a gift unless it is a gift.   I'd have him check with the bank that previously refused him a mortgage if putting both of you on a mortgage would allay their concerns.  Your cash flow would be paying the mortgage payment and if you failed to do so, then they could fall back on his.  That may make more sense to them, even if they would deny each of you a loan on your own.  This works for them because either of you is responsible for the whole loan.  It works for him because he was already willing to be responsible for the whole loan.  And your alternative plan makes you responsible for the whole loan, so this is just as good for you.   At what percentage would you suggest splitting ownership and future expenses? Typically a cash/financing partnership would be 50/50, but since it’s only a 3.5% down-payment instead of 20% is that still fair? Surprisingly enough, a 3.5% down-payment that accumulates is about half the equity of a 20% down-payment.  So your suggestion of a 25%-75% split makes sense if 20% would give a 50%-50% split.   I expected it to be considerably lower.  The way that I calculated it was to have his share increase by his equity share of the ""rent"" which I set to the principal plus interest payment for a thirty year loan.  With a 20% down-payment, this would give him 84% equity.  With 3.5%, about 40% equity.  I'm not sure why 84% equity should be the equivalent of a 50% share, but it may be a side effect of other expenses.  Perhaps taking property taxes out would reduce the equity share.   Note that if you increase the down-payment to 20%, your mortgage payment will drop substantially.  The difference in interest between 3.5% and 20% equity is a couple hundred dollars.  Also, you'll be able to eliminate any PMI payment at 20%.   It could be argued that if he pays a third of the monthly mortgage payment, that that would give him the same 50% equity stake on a 3.5% down-payment as he would get with a 20% down-payment.  The problem there is that then he is effectively subsidizing your monthly payment.  If he were to stop doing that for some reason, you'd have what is effectively a 50% increase in your rent.  It would be safer for you to handle the monthly payment while he handles the down-payment.   If you couldn't pay the mortgage, it sounds like he is in a position to buy out your equity, rent the property, and take over the mortgage payment.  If he stopped being able to pay his third of the mortgage, it's not evident that you'd be able to pick up the slack from him much less buy him out.  And it's unlikely that you'd find someone else willing to replace him under those terms.  But your brother could construct things such that in the face of tragedy, you'd inherit his equity in the house.  If you're making the entire mortgage payment, that's a stable situation.   He's not at risk because he could take over the mortgage if necessary.  You're not at risk because you inherit his equity share and can afford the monthly payment.  So even in the face of tragedy, things can go on.  And that's important, as otherwise you could lose your equity in the house." Let's look at the logical extreme. Two people get a house, no money down, 10 year mortgage. One moves out the day after the closing, and the gal left pays the full mortgage. Why in the world would the one who left be entitled to a dime?  You offer no information about the downpayment or amount paid during the time both lived there. That's the data needed to do any math.