HSA Calculator
Estimate the tax advantages and long-term growth potential of a Health Savings Account (HSA). See your annual tax savings from contributions, projected account balance with investment returns, and how medical expenses affect your balance over time.
The Health Savings Account (HSA) is widely considered the most tax-advantaged investment account in the U.S. tax code. It offers a unique "triple tax advantage": (1) contributions are tax-deductible reducing your current taxable income, (2) earnings grow tax-free inside the account, and (3) withdrawals for qualified medical expenses are tax-free. No other account combines all three benefits. The closest comparison is the Roth IRA (tax-free growth and withdrawal) which lacks the upfront deduction.
The catch: only people enrolled in High-Deductible Health Plans (HDHPs) can contribute to an HSA. For 2025, an HDHP has minimum deductible of $1,650 single / $3,300 family and out-of-pocket maximums up to $8,300 single / $16,600 family. HSA contribution limits for 2025: $4,300 self-only / $8,550 family, plus $1,000 catch-up for ages 55+. Contributions can be employee, employer, or both — combined within the annual limit.
This calculator projects the total tax savings from HSA contributions (immediate benefit), the long-term account balance growth (if you pay medical expenses out of pocket and let HSA invest), and the impact of medical expense withdrawals. The most powerful HSA strategy for those who can afford it: pay current medical expenses from cash flow, contribute the max to HSA, invest the HSA balance for decades, and use the HSA in retirement (where Medicare-eligible expenses + general retirement income flexibility make the HSA extraordinarily valuable).
Inputs
Results
Projected Balance
$161,828
Annual Tax Savings
$1,438
Total Investment Growth
$93,828
FICA Tax Savings/Year
$317
HSA Balance Over Time
Annual Tax Savings Breakdown
Year-by-Year Projection
| Year | Contributions | Growth | Medical | Balance |
|---|---|---|---|---|
| 1 | $4,650.00 | $675.50 | $1,500.00 | $8,825.50 |
| 2 | $4,650.00 | $943.29 | $1,500.00 | $12,918.79 |
| 3 | $4,650.00 | $1,229.81 | $1,500.00 | $17,298.60 |
| 4 | $4,650.00 | $1,536.40 | $1,500.00 | $21,985.00 |
| 5 | $4,650.00 | $1,864.45 | $1,500.00 | $26,999.45 |
| 6 | $4,650.00 | $2,215.46 | $1,500.00 | $32,364.91 |
| 7 | $4,650.00 | $2,591.04 | $1,500.00 | $38,105.96 |
| 8 | $4,650.00 | $2,992.92 | $1,500.00 | $44,248.87 |
| 9 | $4,650.00 | $3,422.92 | $1,500.00 | $50,821.80 |
| 10 | $4,650.00 | $3,883.03 | $1,500.00 | $57,854.82 |
| 11 | $4,650.00 | $4,375.34 | $1,500.00 | $65,380.16 |
| 12 | $4,650.00 | $4,902.11 | $1,500.00 | $73,432.27 |
Formula
How to use this calculator
- Enter your annual HSA contribution. 2025 limits: $4,300 self-only / $8,550 family, plus $1,000 catch-up for 55+.
- Enter employer contribution if applicable. Many employers contribute $500-$1,500/year to HSA. The combined total (you + employer) cannot exceed annual limit.
- Enter current HSA balance.
- Enter expected annual medical expenses. Important strategy distinction: paying these out of pocket (letting HSA grow) vs. using HSA to pay (immediate tax-free benefit).
- Enter federal and state tax marginal rates. Most states allow HSA deduction; check yours.
- Set investment return assumption (typically 6-8% for moderate equity allocations).
- Set projection horizon (longer = more powerful, since HSA tax-free growth compounds).
- Review tax savings and projected balance.
- For optimal strategy: maximize contribution, pay medical expenses out of pocket (cash flow), invest HSA aggressively, use for medical in retirement. This produces the largest after-tax wealth.
Worked examples
Standard "pay medical from HSA" approach
Family coverage. $4,000 contribution + $1,000 employer. $3,000 medical expenses paid from HSA. 22% federal, 5% state. 7% return. 20 years. Net annual contribution: $5,000 in, $3,000 out = $2,000 net annual saved. Tax savings on $4,000: $1,080/year + FICA = $1,386/year. Year 20 balance: ~$120,000 Solid result. Tax savings alone over 20 years: $27,720. Plus accumulated balance from net annual additions. This is the most common HSA usage pattern. Provides meaningful current-year tax benefit while building modest retirement reserve.
Optimal "pay medical from cash, invest HSA" approach
Same family. $4,000 contribution + $1,000 employer = $5,000 annual. Pay $3,000 medical from cash flow (not from HSA). Invest HSA. 7% return. 20 years. Annual contribution to HSA: $5,000 in, $0 out from HSA = $5,000 net annual added. Tax savings on $4,000: $1,386/year (same as before). Year 20 balance: ~$220,000 The "pay medical from cash" approach produces a much larger HSA balance because the medical expenses don't reduce the invested principal. By age 65, the HSA can fund retirement medical expenses tax-free OR (Medicare-eligible expenses) provide additional retirement income. Critical caveat: this approach requires having cash flow to pay $3,000/year of medical expenses without dipping into HSA. Many families can't afford this and need to use HSA for current medical bills.
Long-term aggressive HSA strategy
30-year-old, family coverage, max contributions $8,550/year. Pay medical out of pocket. 30 years to age 60. 7% return. Annual contribution: $8,550 After 30 years: ~$870,000 in HSA Tax savings each year at 24% bracket + 5% state + 7.65% FICA = 37%: $3,164/year Total tax savings over 30 years: ~$95,000 Total wealth created from HSA strategy: $870K + $95K tax savings ≈ $965K For higher-income earners able to max out HSA AND pay medical from cash flow, the long-term HSA wealth potential is extraordinary. The HSA functions like an additional Roth IRA but with the upfront deduction Roth doesn't offer.
When to use this calculator
Use this calculator if you're enrolled in (or considering) a High-Deductible Health Plan with HSA eligibility, planning your annual HSA contribution amount, or evaluating long-term HSA strategy.
For HDHP/HSA decision: HDHPs have lower premiums but higher deductibles. HSA eligibility partially offsets the higher out-of-pocket exposure. For healthy individuals with adequate cash flow, HDHP + HSA often beats traditional plans economically. For those with chronic conditions or expensive ongoing medical needs, traditional plans may be better.
Pair with: BMR/calorie calculators (for general health tracking), the budget-calculator (for cash flow planning), and retirement-savings/IRA/401(k) calculators (since HSA is a powerful supplement to traditional retirement accounts).
The HSA "stealth retirement account" strategy:
1. **Max HSA contribution every year.** 2025: $4,300 self / $8,550 family. The contribution is your tax deduction.
2. **Invest the HSA aggressively.** Most HSA providers offer mutual fund options. Treat HSA investments like a long-term IRA — equity-heavy for long horizons.
3. **Pay current medical expenses from cash flow.** This is the key — keep the HSA invested, not drawing down.
4. **Save all medical receipts.** You can reimburse yourself from the HSA at any time (no time limit). So $50K of medical expenses paid from cash in your 30s and 40s could be reimbursed tax-free from HSA in your 60s — converting "saved receipts" into tax-free retirement income.
5. **Use HSA for medical in retirement.** Medicare premiums, prescriptions, dental, vision, long-term care insurance — all qualified medical expenses payable tax-free from HSA.
6. **For non-medical needs after 65.** HSA functions like a Traditional IRA — taxable as income but no 10% penalty. So even non-medical use is tax-advantaged in retirement.
For high-income earners able to execute this strategy fully, the HSA can build $500K-$1M+ over a career, dwarfing the contribution amounts. It's the single most tax-efficient account in the U.S. tax code.
Common mistakes to avoid
- Spending HSA on current medical expenses instead of investing. The biggest mistake. Paying medical from cash flow and letting HSA invest produces dramatically more long-term wealth.
- Leaving HSA in cash. Most HSA accounts allow investment in mutual funds — use this. Cash balance earns near-zero return while the triple tax advantage compounds slowly.
- Not contributing because "I don't want HDHP." Even occasional HSA eligibility (1 year between jobs, partner has HDHP) allows partial contribution. Use what you can.
- Forgetting catch-up contributions. Ages 55+ can contribute additional $1,000/year. Easy to miss.
- Not saving receipts. Saving medical expense receipts paid from cash means you can reimburse yourself from HSA decades later — creating tax-free retirement income.
- Closing HSA when leaving employer. HSA is fully portable — keep it. Roll to a low-fee HSA provider (Fidelity offers free HSA with full investment options) for long-term management.
Frequently Asked Questions
Sources & further reading
- Health Savings Accounts (HSAs) — U.S. Internal Revenue Service
- HSA Contribution Limits — annual updates — U.S. Internal Revenue Service
- High Deductible Health Plans and Health Savings Accounts — U.S. HealthCare.gov