College Savings Calculator
Estimate how a 529 plan grows over time
How to Use This Calculator
Enter what you already have saved, how much you plan to add each month, how many years until your child starts college, and an expected annual return. The calculator projects the total using standard compound growth math - the same math a real 529 plan provider uses to show you projections.
The bar shows the split between money you actually put in (contributions) and money the investment earned on its own (growth). The earlier you start, the bigger that growth slice gets, because compounding needs time to work.
What Is a 529 Plan?
A 529 plan is a tax-advantaged savings account specifically for education costs, available in every U.S. state. Money you contribute grows tax-free, and withdrawals are also tax-free as long as they're used for qualified education expenses - tuition, room and board, books, and in many cases K-12 tuition too.
You don't have to use your own state's plan, and the account stays in your name as the owner, with your child as the beneficiary. If one child doesn't use all the funds, most plans let you switch the beneficiary to a sibling without penalty.
The Math Behind the Projection
This calculator uses the standard future-value formula for a starting lump sum plus regular monthly contributions:
P = current savings, PMT = monthly contribution, r = annual return ÷ 12, n = total months
This is compound interest at work - the same idea behind the percentage and exponent lessons on this site, just applied to money instead of numbers on a page. Each month's growth is calculated on the new, larger balance, not just the original amount.
What Return Rate Should You Use?
Most 529 calculators default to 6% average annual return as a reasonable long-term planning assumption, since 529 portfolios are usually invested in a mix of stocks and bonds that shifts more conservative as college gets closer. Some planners use 7% for a 10+ year horizon and 5% for a more conservative estimate.
| Time Until College | Typical Assumption | Why |
|---|---|---|
| 10+ years | 6-7% | More time to ride out market ups and downs |
| 5-9 years | 5-6% | Portfolio starts shifting toward bonds |
| Under 5 years | 3-5% | Mostly conservative, capital-preservation focus |
These are general planning ranges, not guaranteed returns. Actual results depend on the specific plan and investments chosen.
Why Starting Early Makes Such a Big Difference
Two families saving the same total amount can end up with very different balances depending on when they started. Someone contributing $150 a month for 15 years puts in $27,000 total but could end up with significantly more than that once growth compounds - while someone starting the same monthly amount only 5 years before college puts in just $9,000 and has far less time for growth to add up.
That gap isn't from contributing more. It's purely the effect of time on compounding. This is the same reason a small head start on saving usually beats a bigger contribution made later.
Common Questions
- What if I can only save a small amount? Any amount started early beats a larger amount started late. Even $25-$50 a month adds up meaningfully over 10+ years.
- Do I lose the money if my child gets a scholarship? No - you can withdraw an amount equal to the scholarship without the usual penalty, though it may still be taxed as income.
- Is there a state tax benefit? Many states offer a state income tax deduction or credit for contributions to their own 529 plan. Check your specific state's rules.