College costs don't rise at the same rate as everyday inflation — tuition has historically climbed faster than the general Consumer Price Index for decades, which means projecting "today's cost" forward using regular inflation assumptions will significantly underestimate what you'll actually need.
A realistic college savings projection uses a college-specific inflation rate (often estimated around 5% annually, compared to the Federal Reserve's roughly 2% general inflation target) applied to today's cost, compounded over however many years remain until enrollment. From there, a 529 plan projection works the same way any other tax-advantaged compound growth calculation does: current balance plus monthly contributions, growing at your expected investment return until the target date.
How the Target and Growth Are Calculated
Future Annual Cost = Today's Annual Cost × (1 + College Inflation Rate)^(Years Until Enrollment)
529 Projected Balance uses the same compound growth formula as any investment account: current balance plus monthly contributions, compounding at your expected return over your savings timeline.
A Worked Example
If today's annual college cost is $28,000 and enrollment is 10 years away, applying 5% college inflation projects a first-year cost of about $45,600 — 63% higher than today's sticker price. Starting a 529 plan with $5,000 now, contributing $250/month, earning 6% for those same 10 years, projects to a balance of roughly $46,300 — just about covering that first year's inflated cost, with the remaining years of a typical 4-year program requiring either continued saving, other funding sources, or financial aid.
Common Mistakes to Avoid
- Using general inflation instead of college-specific inflation: this consistently understates future costs — always use a higher rate for education-specific projections.
- Only projecting one year instead of the full program length: a 4-year program compounds the inflated cost across each additional year, not just the first.
- Starting late: because compound growth needs time, starting a 529 at birth versus starting when a child is 10 produces a dramatically different projected balance for the same monthly contribution.
- Forgetting 529 withdrawals are tax-free for qualified expenses: this makes a 529 meaningfully more efficient than a taxable account for education-specific savings, similar to how a Roth IRA works for retirement.
Bottom Line
Projecting college costs requires accounting for education-specific inflation, not general inflation. Use a 529 Plan Calculator to project your realistic future cost and see whether your current savings plan is on track to cover it.