How this calculator works
This calculator works backward from a college cost target you set to the monthly savings needed to reach it by the time your child starts college, given what you have already saved and an assumed investment return. Many families use a tax-advantaged education savings account, such as a 529 plan in the United States, to hold these contributions, though the math here applies to any dedicated savings or investment account.
Because actual college costs vary enormously by school type, location, and years of attendance, this calculator asks you to enter your own expected total cost rather than assuming a figure. Use a number that reflects the specific schools or type of school (in-state public, out-of-state public, or private) you are planning for, and revisit it periodically as estimates change.
The formula
Required monthly deposit: PMT = (Goal − Current savings × (1+i)^n) × i ÷ ((1+i)^n − 1)i = annual return ÷ 12 · n = months until college start · Goal = expected total college costThis is the same required-monthly-deposit annuity formula used on the savings goal calculator on this site, applied with the years between now and the college start age.
Worked example: age 8 today, college at 18
- Child is 8, college starts at 18, giving 10 years (120 months) to save.
- $10,000 already saved, targeting an $80,000 total cost, at a 6% annual return compounded monthly.
- The existing $10,000 grows on its own to roughly 10,000 × (1.005)^120 ≈ $18,194 by the time college starts.
- The remaining roughly $61,806 needed must come from monthly deposits, which works out to about $377 a month over the 10 years.
Frequently asked questions
What college cost should I use?
Enter your own estimate rather than relying on a single published average, since costs differ widely between in-state public, out-of-state public, and private institutions, and change from year to year. Ballpark ranges published by sources like the College Board or a specific school's net price calculator are reasonable starting points to research separately.
Should I use a 529 plan or a regular investment account?
A 529 plan or similar tax-advantaged education savings account is worth researching for its potential tax benefits on qualified education expenses, but this calculator's math applies the same way regardless of account type — only the return rate and any tax treatment differ.
What if the required monthly deposit looks too high?
Consider a lower cost target (such as an in-state public school estimate), a longer savings horizon if the child is young, additional funding sources like scholarships or current income at the time, or accepting that savings alone may cover only part of the eventual cost.
Does this account for the fact that college costs may rise before my child attends?
No — enter your expected total cost already adjusted for the years between now and enrollment if you want to account for future cost growth; the calculator does not apply its own cost-inflation assumption.
How much does starting to save earlier reduce the required monthly deposit?
Starting earlier gives both your current savings and each future monthly deposit more months to compound, and spreads the remaining goal over more deposits, so the required monthly amount from this calculator's formula drops as the number of months until college increases, all else being equal. In the worked example on this page, starting at age 8 with 10 years to go requires about $377 a month; starting several years later toward the same $80,000 goal with the same $10,000 already saved would leave less time for growth and fewer deposits to spread the remaining amount over, so the required monthly deposit would come out higher, not lower.