529 Planning Calculator
Most 529 tools force you to pick one question: how much will my fund grow, or how much do I need to save? They are the same question asked from opposite ends, and answering only one of them leaves the plan half built. A growth projection that never meets the future bill cannot tell you whether you are short, and a savings target that ignores what you have already saved will overstate the monthly amount and scare you off starting.
The 529 Planning Calculator below runs both sides in one pass. Enter the cost you are aiming at in today’s dollars, your child’s current age and college start age, what you have already saved, an expected return, and a college cost inflation rate. It inflates the target to the year your child enrolls, grows your current savings to that same date, subtracts one from the other, and solves for the exact monthly contribution that closes the remaining gap. That is fund growth projection and goal planning in a single tool, with the shortfall stated in dollars instead of hidden.
Estimates only, not financial or tax advice. Returns are assumed to be smooth and constant, while real markets move up and down, and college costs vary widely by school. State 529 tax benefits differ by state and are not included in the projection.
Quick Answer
Key takeaways
- Two numbers drive the whole plan: the inflated future cost and the grown value of what you have already saved. The monthly figure is just the gap between them, spread over the months left.
- Starting earlier beats saving harder. On these same assumptions, starting at birth takes $381.43 a month, starting at age 5 takes $549.06, and waiting until age 10 takes $917.70.
- Growth does heavy lifting on long horizons: in the worked example, $54,950.59 of the $150,603.85 bill is paid by returns, not deposits.
- A 529 is a tax wrapper, not an investment by itself. Earnings used for qualified education expenses are federally tax free; the return you earn still depends on the portfolio you pick inside the plan.
- You do not have to fund 100 percent. Set the target to the share you realistically want to cover and let financial aid, cash flow and your child cover the rest.
- Quick Answer
- How this planner thinks: a race between two compounding curves
- The formula, step by step
- Worked example: the pre-filled plan, checked line by line
- What waiting costs: the same plan started at three ages
- Choosing your return and inflation assumptions honestly
- The tax rules that make a 529 worth the wrapper
- What competing calculators miss
- Frequently asked questions
- Add This Calculator to Your Website
How this planner thinks: a race between two compounding curves
A 529 plan is a state sponsored account under section 529 of the tax code, described in the Internal Revenue Service guidance on 529 plans: questions and answers. Money goes in after tax, grows tax deferred, and comes out federally tax free when it pays for qualified education expenses. The planning problem is a race. On one side, college costs compound upward at the inflation rate you enter. On the other side, your savings compound upward at the return you expect. The calculator runs both curves to the same enrollment date and measures the distance between them.
That framing explains the result that surprises most parents: the monthly amount is far more sensitive to the start age than to small changes in the target. Adding $20,000 to the target adds a fixed slice to the gap. Losing five years removes 60 monthly deposits and five years of compounding on everything, so the required deposit jumps far more. If you want a pure growth view of an existing balance with a fixed monthly deposit already chosen, the 529 plan growth calculator projects that balance forward year by year. This page solves the reverse problem: it starts from the bill and works back to the deposit.
The formula, step by step
Set the clock. Years to save = college start age minus current age. Age 5 to age 18 gives 13 years, or 156 monthly deposits.
Inflate the target. Future cost = today’s target cost multiplied by (1 + inflation rate) raised to the years to save. Here: $100,000 growing at 3.2% for 13 years becomes $150,603.85.
Grow what you have. Future value of current savings = current savings multiplied by (1 + return) raised to the years to save. Here: $10,000 at 6% for 13 years becomes $21,329.28.
Measure the gap, then solve for the deposit. Amount still needed = future cost minus the grown savings: $129,274.56. The monthly deposit is that gap divided by the annuity factor for monthly compounding at the same return, which gives $549.06. If the return is zero, the gap is simply divided by the number of months.
Worked example: the pre-filled plan, checked line by line
The calculator above is pre-filled with this exact case, and every figure below is what it returns when you press Calculate.
| Figure | Value |
|---|---|
| Target cost in today’s dollars | $100,000 |
| Years to save (age 5 to age 18) | 13 years (156 months) |
| Future cost at 3.2% inflation | $150,603.85 |
| Current savings of $10,000 grown at 6% | $21,329.28 |
| Amount still needed | $129,274.56 |
| Monthly saving required | $549.06 |
| Total you set aside ($10,000 start plus 156 deposits) | $95,653.26 |
| Supplied by investment growth | $54,950.59 |
Read the last two rows together: you fund about 64 percent of the future bill out of pocket and growth funds the rest. That split is the real product of a 529 started early. Start the same plan at age 10 and you deposit more in total, not less, because eight years of growth cannot do the work thirteen years did. Families comparing this goal against a general education fund rather than a 529 specifically can run the same target through the education savings calculator to see the non-529 version of the math.
What waiting costs: the same plan started at three ages
| Start age | Years to save | Future cost | Monthly saving needed |
|---|---|---|---|
| Birth (age 0) | 18 | $176,292.79 | $381.43 |
| Age 5 | 13 | $150,603.85 | $549.06 |
| Age 10 | 8 | $128,658.23 | $917.70 |
The later start faces a smaller inflated target, because the bill has fewer years to rise, and still needs a deposit two and a half times larger. Time is the one input you cannot buy back later. It is also why a modest automatic deposit started now usually beats a heroic deposit planned for next year: the first version is already compounding while the second is still a resolution.
Choosing your return and inflation assumptions honestly
The two rate inputs decide the answer, so pick them like an adult, not like a salesperson. For inflation, the College Board’s Trends in College Pricing series shows published tuition rising faster than general prices over long periods, though the pace has cooled in recent years; 3 to 5 percent is the range most planners test. For returns, remember that age-based 529 portfolios glide toward bonds and cash as enrollment nears, so a flat 6 percent for the whole period is already a simplification. Run the calculator three times, at a cautious, middle and optimistic return, and treat the spread as the honest answer. A plan that only works at 9 percent is not a plan.
One more honesty check: the target. Four years of published prices at a private college and four years at an in-state public college are different planets, and many families deliberately target one third to one half of the full sticker price, expecting scholarships, cash flow during college, and a student contribution to cover the rest. The college funding calculator helps you sanity check what share of a specific school’s cost your target really represents before you lock the deposit in.
The tax rules that make a 529 worth the wrapper
What works in your favor
- Earnings grow tax deferred and withdrawals for qualified expenses are federally tax free, per the IRS overview of qualified tuition programs (Topic No. 313).
- Many states add a deduction or credit for contributions to their own plan, which can cut the effective cost of each deposit.
- Qualified expenses are broad: tuition, fees, books, supplies, computers, and room and board for students enrolled at least half time.
- Unused money is not trapped: the beneficiary can be changed to another family member, and up to $35,000 can roll to the beneficiary’s Roth IRA if the account meets the SECURE 2.0 conditions, including the 15-year holding rule.
What to watch
- Non-qualified withdrawals tax the earnings portion as ordinary income plus a 10 percent additional tax, so overfunding has a real cost.
- There is no federal deduction for contributions, and state benefits usually require using that state’s plan.
- Gift tax rules still apply: contributions count as gifts to the beneficiary, with an election to front load five years of annual exclusions at once, often called superfunding.
- Investment choices are limited to the plan’s menu and can usually be changed only twice per calendar year.
Notice what the calculator leaves out on purpose: your state tax benefit. A state deduction effectively discounts every deposit, which means the after-benefit cost of hitting the target is lower than the headline monthly figure in states that offer one. Treat the calculator’s number as the gross deposit and any state benefit as a rebate on top, then price the whole college goal alongside other family goals with the saving for college calculator if you are splitting deposits across siblings.
What competing calculators miss
We reviewed the top-ranking 529 and college savings tools before rebuilding this page. They are strong on projection and weak in three specific places this page closes.
Winning move 1: the gap is the headline, not a footnote. Several leading tools, including the detailed projector at 529plancalculator.com and the growth-first calculators on generalist sites, lead with the projected balance for a deposit you guessed. You still have to iterate by hand, raising and lowering the deposit until the balance meets the bill. This calculator inverts the workflow: you state the goal and it solves for the deposit, then shows future cost, grown savings and the remaining gap as separate audited lines.
Winning move 2: today’s dollars in, enrollment dollars out. Some competitors ask for a future cost directly, which forces you to do the inflation math in your head before you can even start, and others never inflate the target at all, quietly assuming college costs stand still for 13 years. Here you enter the cost as you know it today and the tool carries it forward at your chosen inflation rate, so the $100,000 target honestly becomes $150,603.85.
Winning move 3: the cost of waiting, in one table. Competitor pages describe starting early as wise and leave it as a slogan. The start-age table above prices it: $381.43 a month from birth against $917.70 from age 10 on identical assumptions. That single comparison changes more savings behavior than any paragraph of advice, including this one.
One limit is shared by every tool in this comparison, including this one: none of them can price your state’s tax benefit, your child’s actual school, or financial aid. The projection sets the deposit. The plan still needs a yearly review against real statements and real prices.
Frequently asked questions
It combines fund growth projection and goal planning in one tool. You enter a target college cost in today’s dollars, your child’s ages, what you have saved, an expected return and a cost inflation rate. It inflates the target to enrollment, grows your current savings to the same date, and solves for the monthly contribution that closes the gap: $549.06 a month in the pre-filled example.
First the gap is found: future inflated cost minus the future value of your current savings. That gap is then divided by the annuity factor for monthly deposits compounding at your expected return over the months remaining. At a zero return, the gap is simply divided by the number of months.
A long-horizon planning range of 5 to 7 percent is common for a diversified portfolio, but age-based options reduce risk as college nears, which lowers the expected return in later years. Run the calculator at a cautious and an optimistic rate and plan around the middle, rather than trusting one number.
College costs have historically risen faster than general inflation. The pre-filled 3.2 percent is a moderate assumption; many planners test 3 to 5 percent. Because the target compounds over the full period, moving from 3.2 to 5 percent raises a 13-year target substantially, so test both ends of the range.
No. Many families target a share of the cost, often one third to one half, and cover the rest with scholarships, current income during college, and a student contribution. Set the target field to the amount you actually want the 529 to cover and the monthly figure adjusts automatically.
The money is not lost. You can change the beneficiary to another family member, use up to $10,000 per year for K-12 tuition and certain apprenticeship or student loan costs, or roll up to $35,000 over a lifetime into the beneficiary’s Roth IRA if the SECURE 2.0 conditions are met, including the account being open at least 15 years. Non-qualified withdrawals tax the earnings plus a 10 percent additional tax.
There is no federal annual contribution limit, but contributions are gifts for tax purposes. Amounts above the annual gift tax exclusion per beneficiary can require a gift tax filing, and an election lets one contributor front load five years of exclusions at once. States also set high overall account balance caps per beneficiary.
No. State deductions and credits vary too much to fold into one national projection, and many require contributing to that state’s own plan. Treat the monthly result as the gross deposit; any state benefit you qualify for reduces its effective cost.
Yes, by running the calculator once per child with that child’s ages and target. Each child needs a separate 529 account as beneficiary, and younger children get longer horizons, which is why the same target usually needs a smaller monthly deposit for them.
No. It is a planning estimate built on smooth, constant return and inflation assumptions. Real returns arrive unevenly and college prices change. Review the plan yearly against your actual balance and current costs, and confirm tax questions with a qualified professional.
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References
- Internal Revenue Service, “529 Plans: Questions and Answers” – the federal rules for qualified tuition programs, qualified expenses, and the tax treatment of earnings and withdrawals. IRS: 529 Plans Questions and Answers. Accessed October 2026.
- Internal Revenue Service, Topic No. 313, “Qualified Tuition Programs” – the tax code summary of how 529 earnings are taxed when used for qualified and non-qualified expenses. IRS: Topic No. 313 Qualified Tuition Programs. Accessed October 2026.
- College Board, “Trends in College Pricing and Student Aid” – annual published tuition, fee, room and board data used to ground college cost inflation assumptions. College Board: Trends in College Pricing. Accessed October 2026.
- US Securities and Exchange Commission, Investor.gov, “529 Plans” – investor guidance on how 529 college savings plan accounts work, fees, and investment options. Investor.gov: 529 Plans Glossary and Guidance. Accessed October 2026.
- FINRA, “Saving for College: 529 College Savings Plans” – plain-language overview of contribution rules, beneficiary changes, and state tax considerations. FINRA: Saving for College. Accessed October 2026.
- Federal Student Aid, US Department of Education, “Federal Student Aid” – official information on aid eligibility that families combine with 529 savings when funding the remaining cost. Federal Student Aid: Official Site. Accessed October 2026.