About the HSA Calculator
A Health Savings Account is one of the few places in the tax code where money goes in tax-free, grows tax-free, and can come out tax-free too, provided it's spent on qualified medical expenses. Our HSA Growth & Tax Savings Calculator projects your balance over time and estimates how much you save in taxes by contributing pre-tax.
How It Works
You enter your current HSA balance, planned annual contribution, expected annual return, time horizon, and marginal tax rate. The calculator compounds your current balance plus contributions (split into equal monthly deposits) at your expected return over the years you specify, the same future-value method used across the site's investment calculators. Separately, it multiplies your annual contribution by your marginal tax rate and by the number of years to estimate cumulative tax savings from contributing pre-tax.
Examples
Long-term growth
Starting with a $5,000 balance, contributing $4,150 a year, and earning 6% annually, an HSA can grow to well over $150,000 after 20 years, most of it from investment growth rather than contributions alone.
Tax savings
At a 24% marginal tax rate, contributing $4,150 a year for 20 years saves roughly $19,900 in taxes over that period, on top of the account's investment growth.
Advantages
- Combines investment growth and tax savings into one projection
- Reflects the HSA's unique triple tax advantage that other accounts don't offer
- Useful for deciding how aggressively to fund an HSA versus other retirement accounts
- Shows the long-term payoff of investing HSA funds rather than leaving them in cash
Common Mistakes
- Leaving HSA contributions in cash instead of investing them for long-term growth, missing out on most of the compounding shown here
- Spending HSA funds on non-qualified expenses before age 65, triggering income tax plus a 20% penalty
- Not tracking receipts for qualified medical expenses, which can be reimbursed tax-free at any point in the future
- Assuming employer contributions count separately from the IRS annual limit, when they count toward the same cap as your own contributions
Edge Cases to Watch For
- The tax savings estimate assumes your marginal tax rate and contribution amount stay constant every year, which real income and tax brackets rarely do exactly.
- This projection doesn't account for annual IRS contribution limits, which change periodically and differ for self-only versus family coverage, so check current limits before assuming your entered contribution is allowed.
- Growth projections assume a constant annual return with no market volatility, which won't match real investment performance year to year.
- Withdrawals for non-qualified expenses before age 65 are taxed as income plus a 20% penalty, a cost this calculator doesn't model since it assumes qualified medical use.
Common Use Cases
- Projecting long-term HSA growth if used as a supplemental retirement account
- Estimating the tax benefit of maximizing HSA contributions each year
- Comparing HSA funding against other tax-advantaged accounts like a 401(k) or IRA
- Planning ahead for future medical expenses in retirement