HSA Calculator
Project what a health savings account is worth after years of contributions and investment growth — and see how much of that only exists because an HSA is never taxed on the way in, along the way, or on the way out.
Your HSA
Growth assumptions
How to use this calculator
1. Set your coverage and your age
Self-only and family high-deductible plans have different IRS caps, and the family cap applies even if only one person on the plan owns the account. Your age matters for one reason: from 55 onward you get an extra thousand dollars of room per year. The box under the contribution fields shows the exact cap the calculator is using and how much of it is still unclaimed.
2. Split the contribution between you and your employer
Both halves land in the same account and both count against the same limit, so a generous employer seed shrinks how much you can add yourself. Keeping them separate here matters because the seed is money that was never in your paycheck, while your own contribution is what actually cuts this year's tax bill.
3. Decide whether the account pays your medical bills
The medical spending field is the single biggest lever in the projection. Draining four thousand dollars a year keeps the balance near flat; paying those bills from your checking account instead and letting the HSA compound turns it into a stealth retirement account. Run it both ways and look at the gap in the year-by-year table.
4. Read the comparison, not just the balance
The big number at the top is only half the story. The comparison panel takes the identical gross dollars, taxes them at your marginal rate before they are invested, then taxes the growth each year — which is what would happen in an ordinary brokerage account. The difference between the two ending balances is the entire dollar value of the triple tax advantage.
Health savings account FAQs
What is the HSA triple tax advantage?
An HSA is the only account that is untaxed at all three stages. Money goes in before income tax, the balance grows without any tax on interest, dividends, or capital gains, and withdrawals for qualified medical expenses come out tax-free. A 401(k) taxes the withdrawal, a Roth IRA taxes the contribution, and a brokerage account taxes the growth every year. This calculator prices that difference by running the same dollars through a taxable account beside your HSA.
How much can I put in an HSA?
For 2025 the IRS caps contributions at $4,300 for self-only coverage and $8,550 for family coverage, plus a $1,000 catch-up once you turn 55. That cap covers everything that lands in the account, so anything your employer seeds counts against it. The calculator reads the current limits from a single shared data file, so the figure on the page is the one it actually uses in the math.
At what age does the HSA catch-up contribution start?
55, not 50. HSAs are the exception among retirement-flavored accounts: 401(k) and IRA catch-ups begin at 50, but the extra $1,000 of HSA room only opens in the year you turn 55. If both spouses are 55 or older, each needs their own HSA to claim their own catch-up — a family plan does not double it inside one account.
Do I have to spend the money on medical bills each year?
No. Unlike a health FSA there is no use-it-or-lose-it rule and no deadline for reimbursing yourself. You can pay small bills out of pocket, keep the receipts, let the balance stay invested for decades, and reimburse yourself tax-free at any point in the future. Set the medical spending field to zero to model that strategy, or set it to your real annual spend to see the drag it creates.
What happens to an HSA after age 65?
Qualified medical withdrawals stay tax-free for life, and Medicare premiums count as qualified. From 65 on, non-medical withdrawals are still taxed as ordinary income but the 20% penalty disappears, which makes the account behave like a traditional IRA in the worst case and a tax-free account in the normal case. You must stop contributing once you enroll in Medicare.
Is this calculator exact?
It is a planning estimate. Real returns are not a smooth annual percentage, your marginal rate changes as your income changes, state treatment of HSAs varies (a couple of states still tax them), and payroll contributions also skip FICA in a way this model leaves out — so the true advantage is usually a little larger than what you see here. Use the result to compare strategies, not as a tax filing figure.