Is UC San Diego or San Diego State usually more affordable for in-state students?

The biggest practical tradeoff is that UC San Diego usually has higher tuition and campus fees, while San Diego State often comes in lower on direct billed costs for California residents. Since both schools are in the same city, housing and day-to-day living costs can be fairly similar, so the tuition gap often matters most. In most in-state comparisons, SDSU is the more affordable option overall.

For a California student, UC tuition is typically higher than CSU tuition, and that difference is real before you even get to books, transportation, and personal expenses. If you are looking at the published sticker price alone, SDSU is usually the cheaper school.

Housing is a little less straightforward. Because both are in San Diego, off-campus rent and general living expenses can be expensive at either school. On-campus housing rates can vary by room type and meal plan, but they usually do not erase the broader pattern that SDSU costs less overall for in-state students.

The part that can change the answer is financial aid. UC San Diego may sometimes offer enough need-based aid to narrow the gap or even make it competitive for a particular student, especially for lower-income California residents. But absent unusually strong aid from UCSD, San Diego State is usually the more affordable choice for an in-state student comparing total cost.