DayCents

Savings & Banking

HSA Calculator

An HSA is the only account that is untaxed three times over: deductible going in, untaxed while it compounds, and untaxed coming out for medical costs. Treated as an investment account rather than a spending one, it usually beats every other wrapper available to you.

Tested against worked examplesHow we verify

2026 limits: $4,400 self-only, $8,750 family, plus $1,000 catch-up at 55.

Counts against the same annual limit.

HSA balance at your horizon: $221,376

HSA balance at your horizon

$221,376

Tax-free when spent on qualified medical costs, at any point in your life.

Total contributed
$108,000
Investment growth
$113,376
Income tax avoided
$21,120
FICA avoided
$6,732

7.65% that no other retirement account saves you.

Same money in a taxable account
$168,657
HSA advantage
$52,719
Final balance$221.4K
Contributions$108,00049%
Growth$113,37651%

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Compare scenariosTry three values of one input
HSA Calculator results for three values of Your annual contribution
Your annual contribution
HSA balance at your horizon$204,977$221,376+$16,398$237,774+$32,796
Total contributed$100,000$108,000+$8,000$116,000+$16,000
Investment growth$104,977$113,376+$8,398$121,774+$16,796
Income tax avoided$19,200$21,120+$1,920$23,040+$3,840
FICA avoided$6,120$6,732+$612$7,344+$1,224
Same money in a taxable account$156,854$168,657+$11,803$180,460+$23,606

Every other input stays at the value you set above — currently $4,400 for your annual contribution. Differences are measured against the first column.

Saved scenariosSave this calculation

Saved in this browser only — no account, and nothing is sent to us. Clearing your browser data deletes them.

How this calculator works

Contributions are treated as arriving once a year and compounding at the given return. Income tax saved is your contribution × marginal rate × years; FICA saved adds 7.65% on payroll deferrals only. The taxable comparison starts from after-tax dollars and compounds at the return less a 0.5% annual drag for dividends and rebalancing — a rough stand-in for the real, situation-specific figure.

Contribution limits are not enforced here; check the current IRS figures before setting your payroll deferral. State treatment varies — California and New Jersey tax HSA contributions and growth. This projection assumes the balance stays invested and untouched, which is what makes the numbers large.

What this assumes

  • Eligibility requires a qualifying high-deductible health plan; this does not check that you have one.
  • A constant investment return, and that the balance is actually invested rather than left as cash — many providers default to cash.
  • Qualified medical withdrawals are tax-free. After 65, non-medical withdrawals are taxed like a traditional IRA.

What changes this number

Whether the balance is invested
The single biggest difference between an HSA used as a spending account and one used as a retirement account.
Paying medical costs out of pocket
Leaving the HSA untouched is what turns it into the most tax-advantaged account available.
Time
Three tax advantages compounding together make the horizon matter more here than in a taxable account.

A worked example

Take the $5,400 a year for 20 years scenario. These figures are produced by the calculator above, not written alongside it, so they always match what the tool returns.

What you enter

Your annual contribution
$4,400
Employer contribution
$1,000
Years invested
20 years
Annual return
7%

What it returns

HSA balance at your horizon
$221,376
Total contributed
$108,000
Investment growth
$113,376
Income tax avoided
$21,120
FICA avoided
$6,732

Try an example

Frequently asked questions

What is the HSA triple tax advantage?

Contributions are deductible, growth is untaxed, and withdrawals for qualified medical expenses are untaxed. No other US account does all three. Payroll contributions add a fourth break by escaping the 7.65% FICA tax, which a 401(k) never does.

Who can contribute to an HSA?

You must be covered by a qualifying high-deductible health plan, with no other disqualifying coverage, and not enrolled in Medicare or claimed as a dependent. Eligibility is checked monthly, so mid-year changes prorate the limit.

Should I invest my HSA or keep it in cash?

That depends on whether you can pay medical bills from other money. If you can, invest the balance and let decades of compounding run. If a $3,000 bill would go on a credit card instead, keep at least the deductible in cash — the tax break is not worth 20% interest.

What happens to an HSA after 65?

The 20% penalty for non-medical withdrawals disappears. You can spend it on anything, paying ordinary income tax like a traditional IRA, or keep using it tax-free for medical costs — including Medicare premiums, which qualify. That makes it strictly better than a 401(k) at that point.

Can I reimburse myself for an old medical expense?

Yes, and there is no deadline. An expense incurred after the HSA was opened can be reimbursed decades later, provided you kept the receipt. Some people pay out of pocket for years, let the account compound, then withdraw tax-free against a folder of old receipts.

Disclaimer: DayCents provides this calculator for educational purposes only. Results are estimates based on your inputs and the stated assumptions — they are not financial advice, a quote, or an offer of credit. Consult a qualified financial professional before making major money decisions.