Today's tuition, tomorrow's price.

• Cost defaults: College Board, Trends in College Pricing 2025 (Table CP-1), 2025-26 average published tuition and fees plus housing and food: public 4-year in-state $25,850, public 4-year out-of-state $45,780, private nonprofit 4-year $60,920. Published prices, before grant aid.
• Costs grow at the yearly rate you set until each college year. The 529 grows monthly at a constant return until college starts; money still invested during college, aid, scholarships and taxes aren't modeled.
• Every number is hypothetical and depends entirely on what you enter. Small changes in assumptions can change results a lot.
• Returns are smooth and constant in the single-number projection; real returns vary every year, and real markets can do better or worse than anything shown.
• Inflation is a single constant rate you choose (except in historical replays, which use the actual CPI of each year).
• Growth compounds monthly (or at the contribution frequency) and contributions are made at the end of each period.
• No taxes unless you turn on the simplified tax drag (all positive growth taxed each year at your rate, which overstates tax for buy-and-hold). No fees unless you set one.
• Inputs stay in your browser. Saving uses this device's local storage; a share link contains the numbers you entered, so anyone with the link can see them.

Coteau may be wrong. Check every number yourself, and talk to a licensed professional before acting on anything.