HSA Calculator
Calculate your HSA contribution limit, the immediate tax saving from contributing, and what the balance could grow to if invested.
How to use this calculator
- 1Choose your HDHP coverage type and whether the $1,000 catch-up applies.
- 2Enter what you and your employer are contributing this year to see your remaining room and immediate tax saving.
- 3Set years to grow above 0 to see a long-run projection if the balance is invested rather than spent on current medical costs.
How the calculation works
Contribution limit = Self-only or family base limit + $1,000 catch-up (55+)- Base limit
- $4,300 self-only or $8,550 family for 2025, combining your contribution and any employer contribution
- Tax saving
- Deductible contribution × your marginal tax rate
The limit applies to the combined total of your contribution and any employer contribution — it does not double if both contribute.
The catch-up amount is fixed at $1,000 and, unlike the base limits, is not indexed for inflation.
Worked example
Self-only coverage, $3,000 contributed plus a $500 employer contribution
- 1.2025 self-only limit: $4,300.
- 2.Total contribution: $3,000 + $500 = $3,500 — under the limit, so nothing is capped.
- 3.Remaining room: $4,300 − $3,500 = $800.
- 4.Tax saving on your $3,000 deductible contribution at 30%: $3,000 × 30% = $900.
Result: $800 of room remaining; $900 immediate tax saving
The only account with three tax advantages at once
A Health Savings Account is frequently described as "triple tax-advantaged," and the description is literal rather than marketing: contributions reduce taxable income in the year they are made, the balance grows completely tax-free however it is invested, and withdrawals for qualified medical expenses are never taxed at any point. A traditional 401(k) gets the first two advantages but taxes withdrawals; a Roth IRA gets the last two but not the first. An HSA is the only common account structure that gets all three simultaneously, which is why financial planners frequently rank maxing it out ahead of other retirement accounts once any employer match elsewhere has been captured.
Eligibility requires a high-deductible health plan
An HSA is not available to everyone — eligibility requires being enrolled in a qualifying High Deductible Health Plan (HDHP) and having no other disqualifying health coverage (including, generally, being enrolled in Medicare). The contribution limit itself depends only on whether that HDHP covers just the account holder or the whole family, not on income, making it one of the few tax-advantaged accounts with no income phase-out at all.
Spend it or invest it
Unlike a Flexible Spending Account, an HSA has no "use it or lose it" rule — unspent balances carry over indefinitely and remain the account holder's property even after changing jobs or health plans. Many HSA providers allow the balance to be invested in funds once it exceeds a set minimum, similar to a retirement account, which is what makes the long-run growth projection meaningful for anyone who can afford to pay current medical costs out of pocket and let the HSA balance itself compound for decades.
After 65, it behaves like a second traditional retirement account
Once the account holder turns 65, HSA funds can be withdrawn for any purpose, not just medical expenses, with the withdrawal simply taxed as ordinary income — the same treatment a traditional 401(k) or IRA withdrawal receives, without the 20% penalty that applies to a non-medical withdrawal before 65. This makes an HSA that is invested and left largely untouched during working years function as a genuinely useful supplemental retirement account, on top of whatever it eventually covers for actual medical spending.
What this assumes, and where it stops
Assumptions
- The contribution limit applies to the combined total from you and your employer, split so your own contribution is treated as capped first when the combined total exceeds the limit.
- The tax saving shown is federal-plus-state as a single combined rate you enter; it does not model the FICA/payroll-tax saving that contributions made directly through payroll (rather than after-tax and deducted at filing) can also receive.
- The growth projection assumes the full annual contribution is invested and left to compound, rather than being spent on medical costs as they occur.
Limitations
- Eligibility rules (HDHP enrollment, no disqualifying other coverage, no Medicare enrollment) are not checked — this calculator assumes you already know you are eligible.
- Contributing above the limit triggers a 6% annual excise tax on the excess until corrected, which is mentioned but not calculated here.
- Investment returns are assumed constant, which real markets never deliver in a straight line.
Common questions
What happens if I contribute more than the limit?
The excess amount is subject to a 6% excise tax for every year it remains in the account, on top of losing the tax deduction on that portion. Excess contributions can be withdrawn before the tax filing deadline to avoid the penalty — most HSA providers have a specific process for this correction.
Can I use HSA funds for anything other than medical expenses?
Before 65, a non-medical withdrawal is taxed as income plus a 20% penalty — similar to an early retirement account withdrawal, but steeper. After 65, non-medical withdrawals are simply taxed as ordinary income with no penalty, which is what makes a well-funded HSA function as a second retirement account later in life.
Sources
- IRS Revenue Procedure 2024-25 — HSA contribution limits — US Internal Revenue Service
Formula and content last reviewed on .
Results are estimates for information only, not professional advice.
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