The Latest in College Pricing: Tuition at 10 Percent of Your Income

College tuition will cost no more than 10 percent of parental adjusted gross income. That’s it. Grab the figure from Line 11a of your 1040 form, and divide by 10.

Starting today, those are the instructions for anyone interested in applying to Whitman College, a small liberal arts college in Walla Walla, Wash.

The school is one of a small but growing number of institutions that are finally answering the extremely reasonable question that families have asked in vain for decades: Why can’t you just tell us the price we’ll pay without having to apply and get in first?

“We’re not hiding the cost of college behind secret formulas,” the school now proclaims on its website.

Last month, Brandeis University made a similar move by introducing a tool allowing prospective students and their families to upload tax forms and high school transcripts in exchange for a “you will pay” figure.

What’s in it for you is clear. What’s in it for the schools may surprise you.

Whitman has seen a notable falloff in applications from the upper middle class. Many of those families have high enough incomes to disqualify themselves from much need-based financial aid, but they don’t have enough money to afford the school’s annual list price of close to $90,000.

But even at a significant discount, often in the form of so-called merit aid, those families provide revenue that is above average for the school. Whitman, like a vast majority of colleges and universities, desperately wants its net tuition revenue per student to rise. It hopes to use transparency as a form of competitive advantage.

Here’s how it will work.

First, that 10 percent figure applies to tuition only. Room and board will cost an additional $16,000 this coming school year, and travel costs, books and a student fee add to the price.

To get need-based aid and participate in the 10 percent program, you’ll eventually need to fill out the Free Application for Federal Student Aid (FAFSA) to verify your income, but the much more detailed CSS Profile aid qualification form is not a requirement. That means Whitman will not make you hand over only-on-the-CSS-form information about, say, your home equity.

The 10 percent offer applies for up to four years of college at Whitman. Each year, you recertify your income via the FAFSA. If those earnings change, so will the tuition. Things generally work differently for international and undocumented students, which the school outlines in its F.A.Q.

If you want to complete the CSS Profile form for Whitman, however, you can. Families with high medical expenses or multiple students in college at once may qualify for more need-based financial aid than the 10 percent figure yields, which is why the 10 percent formula has a “you’ll pay no more than” construction.

And merit aid still exists. A family earning $600,000 — or $6,000,000 — may not pay full price if the applicant qualifies for some of it. The school awards up to $35,000 in such aid per year, which may yield a bigger discount than the 10 percent formula does for some other families as well.

In the class that entered Whitman last year, 6 percent paid the full price. The annual net tuition revenue per student is just over $19,000, not including room and board, said Adam Miller, vice president for admission and financial aid.

That net tuition figure is just an average, though. Whitman meets the full financial need (for all costs, not just tuition) of every student it accepts, including people with very low incomes who pay the college little or nothing. It’s also “need aware,” like many other private colleges that lack gargantuan endowments. This means it rejects some applicants with high financial need who would get in if they could pay more.

The need-aware policy allows Whitman some financial control. Still, this new initiative comes with risks.

The school said it had run some models using recent applicant data that didn’t show more than a $200,000 swing in either direction. But it is difficult to predict how prospective students will respond to this level of transparency. There might be more applicants, but fewer might accept an offer. Recessions, pandemics and presidents who dislike colleges and scare off many international students can compound uncertainty.

Veterans of Mr. Miller’s trade hope he has nerves of steel. “It makes my stomach flip,” said Christina Lopez, who spent four years as dean of enrollment management at Barnard College and cut her teeth in New York University’s admissions office. “They’re going to be flying the airplane as they build it.”

Ms. Lopez said she also worried some about the families who could benefit from submitting the optional CSS Profile form and might not get or digest the message that filling it out could help a lot. “That is a piece that families will not understand,” she said.

But she’s also rooting for Whitman. She sees so much confusion among the demographic that the school is wooing that she teaches a class on college pricing for those families.

Mr. Miller, with his F.A.Q. on the 10 percent plan, said that he hopes to keep things clear.

“We don’t want to have caveats or lots of things that could be an out clause,” he said. “We want to be crystal clear about what people could expect to pay, because that is what was missing.”