Calculating savings from mortgage interest deduction vs. standard deduction?
Those choices aren't mutually exclusive.  Yes, most discussion of the mortgage interest deduction ignores the fact that for a standard itemizer, much, if not all of this deduction can be lost.  For 2011, the std deduction for a single is $5,800. It's not just mortgage interest that's deductible, state income tax, realestate tax, and charitable contributions are among the other deductions. If this house is worth $350K, the property tax is about $5K, and since it's not optional, I'd be inclined to assume that it's the deduction that offsets the std deduction. Most states have an income tax, which tops off the rest. You are welcome to toss this aside as sophistry, but I view it as these other deductions as 'lost' first.  I'm married, and our property tax is more than our standard deduction, so when doing the math, the mortgage is fully deductible, as are our contributions.  In your case, the numbers may play out differently. No state tax? Great, so it's the property tax and deductions you'd add up first and decide on the value the mortgage deduction brings.  Last, I don't have my mortgage for the deduction, I just believe that long term my other investments will exceed, after tax, the cost of that mortgage. It's true that the standard deduction makes the numbers less impressive. I ran your scenario through my favorite, most complete rent vs buy calculator, and your math isn't far off. However, there are a lot of deductions only available if you itemize. Medical expenses, moving expenses, job expenses, charitable contributions, local income/sales taxes, property tax, private mortgage insurance, etc. Property tax on that house alone is going to be nearly equal to the standard deduction, so the point is nearly moot. Anyways, the above linked calculator handles all of those, and more.
Keep in mind, when talking about other deductions, such as mortgage interest, you need to look at your overall situation and whether the taxpayer is near the standard deduction amount. For some, their interest deduction and property tax are below the standard deduction, and therefore, they'd not itemize. "Depending on what your other deductions are and the amount you are wanting to donate, you can save some money by ""batching"" deductions into every other year. For example, if you are single in 2015, the standard deduction is $6,300. This means the first $6,300 in deductions you have basically don't ""matter"" because the standard deduction is larger. You only ""count"" itemized deductions greater than $6,300. Let's imagine you are donating $10k in 2015 and 2016 and have no other itemized deductions. If you donate in both years, you basically get a net deduction of ($10,000 - $6,300) * 2 = $7,400 over the standard deduction. However, if you donate $10k in 2015 and the next $10k on Dec31, 2015, then you now have donated $20k in 2015 and $0k in 2016. This affects your taxes because you now get ($20,000 - $6,300) = $13,700 in ""bonus"" deductions. You still get the full $6,300 standard deduction in 2016 as well. This can be a significant impact on your taxes (especially if you are married as the married deduction is double the single or have minimal other itemizable deductions).." The eligibilty of the deduction is based on what the borrowed money is used to purchase and NOT what asset is used as collateral.  So at the beginning of your mortgage, 10% of the interest is deductible because the entire loan was used to purchase the condo.  But when you withdraw money from the account the additional interest is usually not deductible.  It can get confusing with all the withdrawals and payments that will be coming in and out of the account if you happen to use it a lot like a chequing account. An easy example would be if you only paid the interest on the loan...  Say you had a $100 000 loan at 5% APY (for simplicity's sake).  After one year, you would have paid $5000 interest.  $500 of the would be deductible given that your office is 10% of the condo.  Then you buy a $1000 couch and continue to only pay interest for the next year.  You would have paid $5100 interest...  $5000 on money borrowed to buy the condo, and $100 on money borrowed to buy the couch.  So you can still only deduct $500. What happens when you pay back $500 against the line of credit?  Could you designate that 100% of the money should be applied to the non-deductible interest?  Or does it have to applied proportionally?  I don't know. I think it'd would be wise to separate the loans somehow.  Manulife may even have some tools to facilitate that.  However, I wouldn't recommend the Manulife One product.  I looked into when I was buying my house two years ago, and at that time it was too expensive.  The rate was the same that other banks were charging for a home equity line of credit (which was prime at the time).  You can replicate the Manulife One in a cheaper way using a traditional mortgage and a home equity line of credit...  The majority of the loan will be the traditional mortgage at (hopefully) a cheap rate.  Then you can use your line of credit as the chequing account. Very simple. If it wasn't rented, it's deductible as a schedule A home mortgage interest. If it was rented, you go into Schedule E land, still a deduction along with any/every expense incurred. The Finance functions in spreadsheet software will calculate this for you.  The basic functions are for Rate, Payment, PV (present value), FV (Future value), and NPER, the number of periods.  The single calculation faces a couple issues, dealing with inflation, and with a changing deposit. If you plan to save for 30 years, and today are saving $500/mo, for example, in ten years I hope the deposits have risen as well. I suggest you use a spreadsheet, a full sheet, to let you adjust for this.  Last, there's a strange effect that happens. Precision without accuracy. See the results for 30-40 years of compounding today's deposit given a return of 6%, 7%, up to 10% or so. Your forecast will be as weak as the variable with the greatest range. And there's more than one, return, inflation, percent you'll increase deposits, all unknown, and really unknowable.  The best advice I can offer is to save till it hurts, plan for the return to be at the lower end of the range, and every so often, re-evaluate where you stand. Better to turn 40, and see you are on track to retire early, than to plan on too high a return, and at 60 realize you missed it, badly.  As far as the spreadsheet goes, this is for the Google Sheets -  Type this into a cell =nper(0.01,-100,0,1000,0) It represents 1% interest per month, a payment (deposit) of $100, a starting value of $0, a goal of $1000, and interest added at month end. For whatever reason, a starting balance must be entered as a negative number, for example - =nper(0.01,-100,-500,1000,0) Will return 4.675, the number of months to get you from $500 to $1000 with a $100/mo deposit and 1%/mo return. Someone smarter than I (Chris Degnen comes to mind) can explain why the starting balance needs to be entered this way. But it does show the correct result. As confirmed by my TI BA-35 financial calculator, which doesn't need $500 to be negative. You understand it perfectly right. The thing with PMI is that when your home price rises (or your loan balance goes down) so that your loan balance is below the 80% of the current house price, the PMI goes away. The higher rate - does not. So, no-PMI option is much better. To the bank, as you suspected. Your calculations are correct. With the PMI you'll pay less interest, and more balance. As to the tax deductions, interest can be deducted, but the PMI - no (starting of 2012, to the best of my understanding, at least). See details here, consult a tax professional for more current information. "This answer is based on Australian tax, which is significantly different. I only offer it in case others want to compare situations. In Australia, a popular tax reduction technique is ""Negative Gearing"". Borrow from a bank, buy an investment property. If the income frome the new property is not enough to cover interest payments (plus maintenance etc) then the excess each year is a capital loss - which you claim each year, as an offset to your income (ie. pay less tax). By the time you reach retirement, the idea is to have paid off the mortgage. You then live off the revenue stream in retirement, or sell the property for a (taxed) lump sum." "First off, the ""mortgage interest is tax deductible"" argument is a red herring.  What ""tax deductible"" sounds like it means is ""if I pay $100 on X, I can pay $100 less on my taxes"".  If that were true, you're still not saving any money overall, so it doesn't help you any in the immediate term, and it's actually a bad idea long-term because that mortgage interest compounds, but you don't pay compound interest on taxes. But that's not what it actually means.  What it actually means is that you can deduct some percentage of that $100, (usually not all of it,) from your gross income, (not from the final amount of tax you pay,) which reduces your top-line ""income subject to taxation.""  Unless you're just barely over the line of a tax bracket, spending money on something ""tax deductible"" is rarely a net gain. Having gotten that out of the way, pay down the mortgage first.  It's a very simple matter of numbers: Anything you pay on a long-term debt is money you would have paid anyway, but it eliminates interest on that payment (and all compoundings thereof) from the equation for the entire duration of the loan.  So--ignoring for the moment the possibility of extreme situations like default and bank failure--you can consider it to be essentially a guaranteed, risk-free investment that will pay you dividends equal to the rate of interest on the loan, for the entire duration of the loan. The mortgage is 3.9%, presumably for 30 years.  The car loan is 1.9% for a lot less than that.  Not sure how long; let's just pull a number out of a hat and say ""5 years."" If you were given the option to invest at a guaranteed 3.9% for 30 years, or a guaranteed 1.9% for 5 years, which would you choose?  It's a no-brainer when you look at it that way." Standard deduction is $6300, and exemption is $4050, totaling $10,350. (For 2016) Twice this for a couple ($20,700). The tax on money just above this is 10%, so the few thousand above will be taxed at a few hundred dollars. Where are you getting the number you showed? Can you edit your question to clarify exactly what you are asking? Talk about coincidence, we just recieved letters from our bank saying that our interest only loans will be going up by 0.46% and if we want to keep our lower rate we will need to change early to P&I. Now our Interest only periods end in 6 months to about 16 months anyway. We have decided to change to P&I early and save on our interest expenses. Why? Because the main purpose of investing is to make money not to save on tax. Even if you are on the highest marginal tax rate for every extra dollar of expenses you spend and claim as a deduction you will only get about 50 cents back through tax savings. If you are on the lowest marginal tax rate your tax savings will reduce to less than 20 cents for every extra dollar spent. If you are investing in order to save on tax you may be investing for the wrong reasons. Your primary reason for investing should be to make money, for wealth creation. A good reason to stay with an Interest only loan for an investment property would be if you require the extra cash flow you would receive compared with an I&P loan. It depends on the relative rates and relative risk. Ignore the deduction. You want to compare the rates of the investment and the mortgage, either both after-tax or both before-tax. Your mortgage costs you 5% (a bit less after-tax), and prepayments effectively yield a guaranteed 5% return. If you can earn more than that in your IRA with a risk-free investment, invest. If you can earn more than that in your IRA while taking on a degree of risk that you are comfortable with, invest. If not, pay down your mortgage. See this article: Mortgage Prepayment as Investment: For example, the borrower with a 6% mortgage who has excess cash flow would do well to use it to pay down the mortgage balance if the alternative is investment in assets that yield 2%. But if two years down the road the same assets yield 7%, the borrower can stop allocating excess cash flow to the mortgage and start accumulating financial assets. Note that he's not comparing the relative risk of the investments. Paying down your mortgage has a guaranteed return. You're talking about CDs, which are low risk, so your comparison is simple. If your alternative investment is stocks, then there's an element of risk that it won't earn enough to outpace the mortgage cost. Update: hopefully this example makes it clearer: For example, lets compare investing $100,000 in repayment of a 6% mortgage with investing it in a fund that pays 5% before-tax, and taxes are deferred for 10 years. For the mortgage, we enter 10 years for the period, 3.6% (if that is the applicable rate) for the after tax return, $100,000 as the present value, and we obtain a future value of $142,429. For the alternative investment, we do the same except we enter 5% as the return, and we get a future value of $162,889. However, taxes are now due on the $62,889 of interest, which reduces the future value to $137,734. The mortgage repayment does a little better. So if your marginal tax rate is 30%, you have $10k extra cash to do something with right now, mortgage rate is 5%, IRA CD APY is 1%, and assuming retirement in 30 years: If you want to plug it into a spreadsheet, the formula to use is (substitute your own values): (Note the minus sign before the cash amount.) Make sure you use after tax rates for both so that you're comparing apples to apples. Then multiply your IRA amount by (1-taxrate) to get the value after you pay future taxes on IRA withdrawals. Certainly, paying off the mortgage is better than doing nothing with the money. But it gets interesting when you consider keeping the mortgage and investing the money. If the mortgage rate is 5% and you expect >5% returns from stocks or some other investment, then it might make sense to seek those higher returns. If you expect the same 5% return from stocks, keeping the mortgage and investing the money can still be more tax-efficient. Assuming a marginal tax rate of 30%, the real cost of mortgage interest (in terms of post-tax money) is 3.5%*. If your investment results in long-term capital gains taxed at 15%, the real rate of growth of your post-tax money would be 4.25%. So in post-tax terms, your rate of gain is greater than your rate of loss. On the other hand, paying off the mortgage is safer than investing borrowed money, so doing so might be more appropriate for the risk-averse. * I'm oversimplifying a bit by assuming the deduction doesn't change your marginal tax rate. When discussing buying a home I often hear people say they like having   a mortgage because they get the benefit of writing off the interest. I assume this is the United States.  You need to also consider that many people can take the standard deduction of about $12k for married couples filing jointly, so even if they itemize the interest, it would only make sense to 'write it off' if you are able to itemize deductions greater than the standard deduction:  Source: http://www.forbes.com/sites/kellyphillipserb/2013/10/31/irs-announces-2014-tax-brackets-standard-deduction-amounts-and-more/ So some people will input the mortgage interest and other related deductions into the computer only to find out that their itemized deductions don't add up. Where it benefits people sometimes is if they have medical bills which are greater than 10% of their income in addition to the mortgage interest. So it benefits them to itemize. There are other major sources of itemization but medical bills are very common. Other common items are auto registration taxes or interest from student loans. It is going to be situation dependent, but if you are within a few years of paying off the mortgage it would make sense to make micropayments to accelerate the payoff date. If you have 30 years to go, it would make more sense to generate an emergency fund, pay off a car, or save up for other things in life than worry about paying off a mortgage. Take the benefit of deducting the mortgage interest if you can, but I imagine that many people would be surprised to hear that it's not always black and white. "In a Roth IRA scenario, this $5,000 would be reduced to $3,750 if we assume a (nice and round) 25% tax rate. For the Traditional IRA, the full $5,000 would be invested. No, that's not how it works.  Taxes aren't removed from your Roth account.  You'll have $5,000 invested either way.  The difference is that you'll have a tax deduction if you invest in a traditional IRA, but not a Roth. So you'll ""save"" $1,250 in taxes up front if you invest in a traditional IRA versus a Roth. The flip side is when you withdraw the money.  Since you've already paid tax on the Roth investment, and it grows tax free, you'll pay no tax when you withdraw it.  But you'll pay tax on the investment and the gains when you withdraw from a traditional IRA.  Using your numbers, you'd pay tax on $2.2MM from the traditional IRA, but NO TAX on $2.2MM from the Roth. At that point, you've saved over $500,000 in taxes. Now if you invested the tax savings from the traditional IRA and it earned the same amount, then yes, you'd end up in the same place in the end, provided you have the same marginal tax rate.  But I suspect that most don't invest that savings, and if you withdraw significant amount, you'll likely move into higher tax brackets. In your example, suppose you only had $3,750 of ""discretionary"" income that you could put toward retirement.  You could put $5,000 in a traditional IRA (since you'll get a $1,250 tax deduction), or $3,750 in a Roth.  Then your math works out the same.  If you invest the same amount in either, though, the math on the Roth is a no-brainer." "The mortgage tax deduction can at most apply to two mortgages. IRS Publication 936 lays this out pretty clearly. There might be other deductions available if you are using the houses as a commercial entity, but that's more ""corporate taxes"" than ""personal taxes"". I know there are tax laws for dealing with interest, depreciation, capital expenses that businesses use."