MBA. PhD. DDS. MFA. There are many different three-letter abbreviations you might focus on when you think about grad school. But there is one abbreviation that all grad-level scholars should think about: ROI. ROI, or return on investment, tells you just how much profit you will truly make from your grad degree, once long-term earnings are measured against the actual cost of graduate school.

It’s probably not possible for you to calculate an exact ROI for your graduate degree. Even if you think you know what you’ll be earning in the years after graduation, there’s no way to be absolutely certain about the future. Still, there are ways to estimate the costs of graduate school, and take an educated, “safe” guess about the long-term earning potential you’ll have with your degree.

Tuition, Fees, and Academic Support

Tuition can be calculated more easily than any other cash cost of graduate school. Schools publish their current tuition rates transparently. And even for a longer graduate degree—a doctorate—it should be easy to include potential long-term tuition rate increases in your estimate. Increases in tuition are usually small and incremental and are generally published before they take effect.

Fees are a little harder to predict. Academic fees outside of the normal tuition structure can fluctuate from one academic term to the next. Textbook fees can be somewhat difficult to predict as well. Some graduate courses have textbooks that cost $10 or $20, while other courses have textbooks that cost $100 or $200, and sometimes even more. To get the best possible estimates, contact prospective grad programs and ask them about the average cost of textbooks and other non-tuition fees.

Finally, remember to account for the costs of academic support. You may need to hire tutoring services during your degree. Moreover, before you even begin your degree, it’s also likely you will purchase test prep material and other services for a grad school entrance exam such as the GMAT or GRE. These preparatory fees can really add up. (For an example calculation of grad school test prep fees, check out this index of possible GRE costs.)

Time Investment

“Time is money,” as the expression goes. And nowhere is this truer than grad school. The amount of time your grad degree takes, in terms of hours per day, days per week, months, and years, is a huge factor in the real cost of graduate school.

When considering grad school costs and ROI in terms of time commitment, there are a number of questions you should ask yourself. Will graduate school keep you from working full time? Will you be able to work at all during graduate school? If you do work while you’re in grad school, what kind of work will you do? And what will this work pay, compared to the earnings you might have if you weren’t in graduate school?

Try to calculate how much money—if any—you’ll earn during graduate school. Also, try to estimate how much of your savings you may dip in to—if any—to compensate for reduced earnings during your studies. Measure this against the kind of earning and spending you’d do if you weren’t in school. This will help you discover the “hidden costs” of graduate school, beyond tuition and fees.

Long-Term Earnings

Once you’ve calculated educational costs and the monetary value of your time commitment you’re ready to see just how much your earnings after graduate school will offset your initial expenses.

These long-term gains are the hardest to calculate, but they’re also the most important part of the calculation. The true return on your investment comes when you start earning, after all.

There are some ways to predict your long-term earnings. If you’ve gotten your graduate degree specifically at the request of your employer, you probably know exactly what kind of raise you’ll get once you complete your degree. And you’ll likely know the long-term schedule for future raises as well. Outside of those employment-based cases, however, knowing what you’ll earn in the long run after you get your grad degree is not-so-easy. But you can make some predictions, based on your intended career path.

If you’re not getting your grad degree for a specific job or employer, you’ll want to look at two pay ranges: the entry level pay range for your post-grad career, and the salary midpoint for your career path. (A good place to look for these ranges is the website for U.S. Bureau of Labor Statistics.) The entry-level pay-range will tell you what you will probably earn in the short run. It’s also a worst-case scenario of sorts. If raises and advances aren’t quick to come, that entry-level pay will be the money that comes in to offset your graduate school costs. The midpoint tells you what you might earn on average over the course of your career. You can treat this as a best-case scenario. The midpoint salary range for your field of work shows how much you will probably be able to profit from your grad school investment on a yearly basis, between graduation and retirement.