Evaluating the opportunity cost
Deciding between prepaying your mortgage and investing your extra cash isn't easy, because each option has advantages and disadvantages. But you can start by weighing what you'll gain financially by choosing one option against what you'll give up. In economic terms, this is known as evaluating the opportunity cost.
Here's an example. Let's assume that you have a $300,000 balance and 20 years remaining on your 30-year mortgage, and you're paying 6.25% interest. If you were to put an extra $400 toward your mortgage each month, you would save approximately $62,000 in interest, and pay off your loan almost six years early. By making extra payments and saving all of that interest, you'll clearly be gaining a lot of financial ground. But before you opt to prepay your mortgage, you still have to consider what you might be giving up by doing so — the opportunity to potentially profit even more from investing.
To determine if you would come out ahead if you invested your extra cash, start by looking at the after-tax rate of return you can expect from prepaying your mortgage. This is generally less than the interest rate you're paying on your mortgage, once you take into account any tax deduction you receive for mortgage interest. Once you've calculated that figure, compare it to the after-tax return you could receive by investing your extra cash.
For example, the after-tax cost of a 6.25% mortgage would be approximately 4.76% if you were in the 24% tax bracket and were able to deduct mortgage interest on your federal income tax return (the after-tax cost might be even lower if you were also able to deduct mortgage interest on your state income tax return). Could you receive a higher after-tax rate of return if you invested your money instead of prepaying your mortgage?
Keep in mind that the rate of return you'll receive is directly related to the investments you choose. All investing involves risk, including the possible loss of principal, and there can be no assurance that any investment strategy will be successful. Investments with the potential for higher returns may expose you to more risk, so take this into account when making your decision.
Other points to consider
While evaluating the opportunity cost is important, you'll also need to weigh many other factors. The following list of questions may help you decide which option is best for you.
- With the current tax legislation, in 2019, the standard deduction of single taxpayers will be $12,200 and for married taxpayers filing a joint return, $24,400. There is a limit of $10,000 for deductions for state and local taxes, including income tax and real estate taxes. Based on this, will you be getting a tax benefit from a mortgage interest deduction?
- What's your mortgage interest rate? The lower the rate on your mortgage, the greater the potential to receive a better return through investing.
- Does your mortgage have a prepayment penalty? Most mortgages don't, but check before making extra payments.
- How long do you plan to stay in your home? The main benefit of prepaying your mortgage is the amount of interest you save over the long term; if you plan to move soon, there's less value in putting more money toward your mortgage.
- Will you have the discipline to invest your extra cash rather than spend it? If not, you might be better off making extra mortgage payments.
- Do you have an emergency account to cover unexpected expenses? It doesn't make sense to make extra mortgage payments now if you'll be forced to borrow money at a higher interest rate later.
- How comfortable are you with debt? If you worry endlessly about it, give the emotional benefits of paying off your mortgage extra consideration.
- Are you saddled with high balances on credit cards or personal loans? If so, it's often better to pay off those debts first. The interest rate on consumer debt isn't tax deductible, and is often far higher than either your mortgage interest rate or the rate of return you're likely to receive on your investments.
- How will prepaying your mortgage affect your overall tax situation? For example, prepaying your mortgage (thus reducing your mortgage interest) could affect your ability to itemize deductions (this is especially true in the early years of your mortgage, when you're likely to be paying more in interest).
- Have you saved enough for retirement? If you haven't, consider contributing the maximum allowable each year to tax-advantaged retirement accounts before prepaying your mortgage. This is especially important if you are receiving a generous employer match. For example, if you save 6% of your income, an employer match of 50% of what you contribute (i.e., 3% of your income) could potentially add thousands of extra dollars to your retirement account each year. Prepaying your mortgage may not be the savviest financial move if it means forgoing that match or shortchanging your retirement fund.
- How much time do you have before you reach retirement or until your children go off to college? The longer your timeframe, the more time you have to potentially grow your money by investing. Alternatively, if paying off your mortgage before reaching a financial goal will make you feel much more secure, factor that into your decision.
What you can do next
Paying off a mortgage early may seem like the happy ending to the American Dream. But you're in for sleepless nights if you don't compare it with your opportunity cost — whether you could make better use of the money you'd spend to retire the home loan.