In a recent Fidelity survey of parents of college-bound children, an all-time high of 72 percent of the respondents were focused on building college nest eggs.

Families suffer from three major knowledge gaps when it comes to saving for college: They struggle to estimate the future cost of college and how much they should save; they do not understand the fundamentals of 529 college savings plans; and they’re confused about how saving for college impacts the student’s financial aid eligibility, according to Fidelity’s “College Savings IQ” survey.

Parents tend to drastically underestimate the sticker price of a four-year college education, according to Fidelity. When the respondents were asked to guess the eventual cost of college based on current costs and the average rate of tuition inflation, they fell short by an average of $110,000. Even the parents of high school students, who may be less than a year away from their first tuition bill, underestimate the price of a four-year degree by an average of $70,000, according to Fidelity.

Nearly half of the respondents, 45 percent, said that they did not have a good idea of how much they should be saving for educational expenses each month.

The lack of knowledge isn’t because families don’t think about or feel urgency concerning college expenses: According to the study, approximately eight in 10 expressed concern for their child taking on significant student debt as a factor that motivated them to save. Nevertheless, 85 percent of the survey participants expected their child to graduate with debt. Parents anticipated that their children would carry $45,000 in student loan debt, on average.

The study’s respondents said that they intend to cover an average of 51 percent of their children’s college costs with personal savings and parental loans, expecting their children to take on approximately 23 percent of the expenses on average, and for scholarships to cover another 19 percent.

More than one-third of the survey respondents, 37 percent, were still paying down student debt of their own. More than two-thirds of parents with children pre-school age or younger carried student loan debt.

Nearly half of the respondents who reported saving for college were doing so within 529 accounts, with a median contribution of $300 each month. Almost all of the 529 users believed that using a dedicated college savings account helped them keep on track towards their goals.

Opening a 529 account correlated with a larger college nest egg: 529 plan owners had accumulated an average of 50 percent more within their accounts, $32,000, than non-529 plan owners, who had saved an average of $21,000.

American parents may be wising up to the benefits of 529 accounts, as the report’s authors note a 34 percent increase in 529 savings plan openings through the first half of 2017 compared to last year.

In the survey, 76 percent of the parents were somewhat or very familiar with 529 accounts, but many showed a lack of understanding about their flexibility and other advantages. The authors argue that more awareness is needed around attributes like the ability to change account beneficiaries at any time, the ability to pay for expenses beyond tuition and school fees, the ability to adjust investments within the accounts, options for the disposition of 529 savings after beneficiaries no longer need the funds and whether they can take advantage of tax deductions and credits for educational savings.

More than two-fifths of the respondents expressed concern that their savings would impact their children’s opportunities to be offered student aid. While most of the assets within 529 accounts are exempt from the need-based financial aid calculations on the FAFSA and other student aid applications, the parents in the survey consistently overestimated how much they would be expected to contribute annually to their children’s college expenses from their 529 plan.

Fidelity conducted a survey of 1,984 parents with college-bound children of all ages with household incomes of at least $30,000 a year in July and August.