Making the decision to attend graduate school is a great investment in your future. That being said, it’s important to not let it lead you into debt. There are lots of obvious expenses related to school, such as tuition, books and supplies, but you’ll need to factor in a lot more to create a sustainable living budget. It might be a challenge making the mental transition back to a school budget if you have been out of school for several years, but starting a budget as soon as possible will save you trouble down the road.

The first step is to write down all of your monthly and annual expenses and divide them into needs vs wants vs savings. Needs are expenses that must be paid on a regular basis, such as rent/mortgage, insurance, groceries, transportation, and utilities. Wants are discretionary purchases such as dining, entertainment and travel. Savings refers to retirement accounts and any “dream” goals. Seeing everything written down is the best way to gain perspective and get a more realistic picture of your financial situation.

Your primary expense will be your tuition, which will vary depending on the program and school you’ve chosen. Keep in mind you’ll also need to account for tuition inflation when thinking about subsequent years. In order to save money, you should first research your school’s financial aid programs, as well as scholarships and any teaching stipends. The exact cost of books and supplies might be hard to quantify, but you can ask for an estimate. In addition to basic supplies, consider the fact that you might need more expensive items such as a new computer or classroom software.

Planning a monthly housing budget requires extensive research on your part. Most schools have a housing section on their website, and there are various apartment finding tools online. There will hopefully be options available within your school, such as student housing vs off-campus. Getting a roommate is another great way to save on rent and general housing costs, if you don’t mind giving up some privacy. Any housing rental agreement should clearly state which utilities are included with the monthly rent. Internet is usually an add-on item, so be sure to count that separately, just like your cell phone bill. If you’re moving, your mode of transportation might change. This could mean an increase in gas if driving more, or having to allow for public transit fares.

With health insurance, it’s vitally important to budget for routine exams, as well as vision and dental appointments. Some schools offer insurance plans for students and will have information on their website.

If you’re already tied down with debt, you will need to factor that into your monthly bills. Some undergraduate loans might be deferrable, but all other debt must be paid to avoid hurting your credit score. It’s important to write down approximately how much you spend each week on groceries and dining. The biggest change will be if you move to an area with a higher cost of living. If you previously cooked at home often, your wallet will be affected if you suddenly start eating out more.

Don’t forget to tend to your mental state of mind as well. It’s important to take time off and spend some discretionary income on entertainment, shopping or travel.

If possible, you should also try to save for your retirement. Graduate students frequently wonder how much they should be saving. It turns out, there is an actual balanced money formula. The BMF takes your net (after tax) pay and sorts it into a ratio based on needs, wants, and savings. The idea behind the BMF ratio is to keep you happy with your spending while also saving for your future. While there is no single ratio for everyone, the standard is 50% needs, 30% wants, and 20% savings. This may seem impossible while tackling all your other bills, but saving is something all grad students should consider.

Once you have all of these expenses written down, prioritize and allocate money accordingly. Secure all of the top expenses first, then determine how thrifty you should be with the rest.