The average annual cost of attending a private four-year college in the United States — including tuition, fees, room, and board — now exceeds $58,000 per year, according to College Board data. At historical tuition inflation of 4–5% annually, a child born today faces a four-year private college bill of approximately $215,000–$250,000 by the time they enroll at 18.
Public universities are cheaper but face the same inflation trajectory. A child born in 2026 entering an in-state public university at 18 is looking at a four-year total that could approach $120,000–$140,000 in 2044 dollars, depending on inflation and the state.
These are not scare numbers designed to paralyze. They are planning numbers — and planning with compound interest working in your favor is materially different from confronting a tuition bill with a lump sum at 17.
What $200/Month From Birth Actually Produces
The most important variable in college savings is not the account type — it's how early you start. The compound interest math on 18 years of monthly contributions is unambiguous.
| Monthly Contribution | Start Age | Years to 18 | At 7% Return |
|---|---|---|---|
| $100/month | Birth | 18 | $45,600 |
| $200/month | Birth | 18 | $91,200 |
| $400/month | Birth | 18 | $182,400 |
| $200/month | Age 5 | 13 | $58,700 |
| $200/month | Age 10 | 8 | $29,600 |
The gap between starting at birth and starting at 10 — for the same $200/month contribution — is approximately $61,600. That's three extra years of full-year public university tuition, from the same monthly commitment, just because you started earlier. Time in the market is superior to trying to time the market, and this principle applies as much to college savings as to retirement.
The Compound Interest Calculator models any starting scenario you have. Enter your child's current age, any existing savings balance, your planned monthly contribution, and a 7% growth rate — the approximate long-run return of a diversified stock market 529 plan in an aggressive age-based allocation. The output shows where you'll land at 18 and whether that covers your target.
Run the numbers
Model your specific scenario
In the Compound Interest Calculator, enter your child's current age in years as the time horizon (subtract from 18). Enter any existing savings as starting balance and your planned monthly contribution. At 7% return, the output is your projected balance at age 18. Compare it to the projected tuition cost from the Inflation Calculator.
What the Inflation Calculator Tells You About Future Tuition
The savings projection is only half the picture. The other half is the tuition cost side — which inflates over time regardless of what markets do. Using the Inflation Calculator to project today's tuition forward at 4.5% annually for 18 years shows what you're actually targeting.
Enter $58,000 (current annual private college cost) at 4.5% inflation for 18 years. The annual cost at your child's enrollment year comes out to approximately $131,000. Multiply by four years: the four-year private college bill is roughly $520,000 in 2044 dollars at this inflation rate. Run the same calculation for a public in-state university at $25,000/year and 3.5% annual inflation: approximately $47,000 per year, or $188,000 over four years.
The gap between what your monthly savings produces ($91,200 at $200/month from birth) and the projected bill ($188,000–$520,000) is your funding gap. Run both calculations and find yours. The gap determines whether $200/month is enough, whether you need to increase contributions, or whether you need to plan for a mix of savings, merit aid, and loans.
Calculate the target
Project what tuition will actually cost
In the Inflation Calculator, enter today's annual tuition cost at 4–5% inflation over the number of years until your child starts college. The result is the annual cost they'll face. Multiply by four for the total target. Then check whether your compound savings model closes that gap.
Trump Accounts: The New Savings Option Launching July 2026
The One Big Beautiful Bill Act created a new savings vehicle for children under 18: Trump Accounts. These launch July 4, 2026. Children born between January 1, 2025 and December 31, 2028 receive a one-time $1,000 government seed contribution automatically. Parents and relatives can contribute up to $5,000 per year combined. Employers can contribute up to $2,500. The account grows tax-deferred until the child turns 18.
The $1,000 government seed is free money. At 7% for 18 years, that $1,000 alone grows to approximately $3,380 by age 18 — before any additional contributions. Adding $200/month on top of the seed produces approximately $94,580 by age 18.
The Trump Account is distinct from a 529 plan. The 529 offers specific tax advantages for qualified education expenses and has no contribution limit beyond state gift tax rules. The Trump Account is more flexible — it functions like a tax-deferred IRA available at 18 — but it's not specifically designed for education, and distributions are taxable as ordinary income. For college savings specifically, a 529 plan may be more tax-advantaged. For general wealth-building for a child, the Trump Account is new, accessible, and now has $1,000 of government money in it if your child was born in 2025 or later.
The Compound Interest Calculator works the same way for both: enter the $1,000 seed as starting balance, your monthly contribution, and 7% return over 18 years. Find the number. Then decide whether you need a 529 on top, whether the Trump Account alone is sufficient, or whether you split contributions between both. The math will guide the decision. Start today — the compounding on those early years is irreplaceable.
Sources
- IRS. "One Big Beautiful Bill Provisions — Trump Accounts." 2026. irs.gov
- J.P. Morgan Asset Management. "One Big Beautiful Bill Act: What Retirement Savers Need to Know." August 2025. jpmorgan.com
- H&R Block. "One Big Beautiful Bill Tax Changes 2026." hrblock.com
- TurboTax / Intuit. "One Big Beautiful Bill Act Tax Law Changes." March 2026. turbotax.intuit.com