College Savings (529) Calculator
Estimate the monthly contribution needed to fully fund four years of college using a 529 plan, factoring in your child's age, education inflation, investment returns, and your current balance.
About this calculator
This calculator projects the future cost of a four-year college education and works backward to a monthly savings target. College costs grow with education inflation — historically 4–6% annually — so future costs are estimated as: Future Cost = currentCollegeCost × 4 × (1 + inflationRate/100)^(18 − childAge). Your existing 529 balance also grows at the expected investment return over the same period: Future 529 Value = currentSavings529 × (1 + investmentReturn/100)^(18 − childAge). The gap between these two figures is funded by monthly contributions, using a future value of annuity formula: Monthly Contribution = (FutureCost − Future529Value) / (((1 + r)^n − 1) / r) / 12, where r = monthly return and n = months until college. 529 plans offer tax-free growth on qualified education withdrawals, making them the most tax-efficient vehicle for this goal.
How to use
Child is 8 years old (10 years until college), current annual cost is $25,000, education inflation 5%, expected return 7%, current 529 balance $10,000. Future cost: $25,000 × 4 × (1.05)^10 = $100,000 × 1.6289 = $162,889. Future 529 value: $10,000 × (1.07)^10 = $10,000 × 1.9672 = $19,672. Gap: $162,889 − $19,672 = $143,217. Monthly return r = 7/100/12 ≈ 0.005833, n = 120 months. Annuity factor = ((1.005833)^120 − 1) / 0.005833 ≈ 173.08. Monthly contribution = $143,217 / 173.08 ≈ $827/month.
Frequently asked questions
What is a 529 plan and what are its tax advantages for college savings?
A 529 plan is a state-sponsored investment account designed specifically for education savings. Contributions are made with after-tax dollars, but all investment growth inside the account is tax-free at the federal level, and withdrawals used for qualified education expenses — tuition, room and board, books, and fees — are also tax-free. Many states offer an additional income tax deduction or credit for contributions made to their state's plan. These compounding tax benefits make 529s significantly more efficient than saving in a regular taxable brokerage account, especially over a 10–18 year horizon where growth can outpace contributions many times over.
What education inflation rate should I use when planning college savings?
College tuition has historically inflated at 4–6% per year — faster than general consumer price inflation. Using 5% is a reasonable middle-ground estimate for planning purposes; using 6% gives a conservative, worst-case projection. Some financial planners recommend modeling at both rates to see the range of possible outcomes. The longer the time horizon, the more sensitive your results are to the inflation assumption — a 1% difference in inflation rate over 15 years can change the projected cost by tens of thousands of dollars, making it worth stress-testing your savings plan with higher estimates.
How does the expected investment return affect my required monthly 529 contribution?
The investment return assumption has a large impact because it determines both how fast your existing balance grows and how effectively new contributions compound over time. A higher assumed return (e.g., 8% for an equity-heavy portfolio) reduces the required monthly contribution significantly, but comes with more volatility risk. A lower return (e.g., 5% for a more conservative allocation) is safer but demands higher monthly deposits. Most financial advisors recommend an age-based allocation — heavier in stocks when the child is young and gradually shifting to bonds as college approaches — which means your effective return will change over time. Using 6–7% is a common planning default for a diversified 529 portfolio over a 10+ year horizon.