HSA vs FSA Calculator
Decide between an HSA or FSA by comparing tax savings, limits, and rollover rules for 2026.
Last updated: April 2026
HSA vs FSA: Which should you choose?
Both HSAs and FSAs allow you to pay for healthcare expenses with pre-tax dollars, saving you money on income taxes. However, they have very different rules regarding eligibility, ownership, and what happens to your money at the end of the year.
HSA (Health Savings Account): Available only to those with a High Deductible Health Plan (HDHP). The money is yours forever, can be invested, and rolls over annually.
FSA (Flexible Spending Account): Available through your employer. It is generally a "use-it-or-lose-it" account, meaning if you don't spend the balance by the end of the year (or grace period), the money goes back to the employer.
How to use this calculator
- 1Check your Tax Rate — Enter your marginal tax bracket (federal + state) to see real dollar savings.
- 2Select Coverage Type — Toggle between Single or Family coverage to see the correct 2026 limits.
- 3Input Contribution — Enter the amount you plan to contribute annually from your paycheck.
- 4Result Comparison — Review the chart to see total financial advantage including employer matches.
Formula & example
Tax Savings = Contribution Amount × Marginal Tax Rate
If you contribute $3,000 to an HSA and your combined tax rate is 25%, you save $750 in taxes ($3,000 × 0.25). Effectively, your $3,000 contribution only 'costs' you $2,250 in take-home pay.
Benefits
Triple Tax Advantage
In an HSA, contributions are pre-tax, growth is tax-free, and withdrawals for medical expenses are tax-free.
Avoid Use-it-or-lose-it
Use this tool to avoid over-contributing to an FSA and losing money.
Investment Growth
See how much HSA space you have left to use as a secondary retirement vehicle.
Use cases
Open Enrollment
Compare plans during your company's benefits selection period.
New Baby or Surgery
Estimate how much to set aside if you know you have upcoming medical costs next year.
Frequently asked questions
Can I have both an HSA and an FSA?+
Generally no, unless the FSA is a 'Limited Purpose FSA' (LPFSA) which covers only dental and vision expenses.
Are HSA/FSA contributions subject to FICA taxes?+
If made via payroll deduction (Section 125 plan), they are exempt from Social Security and Medicare taxes (7.65%), providing even more savings than just income tax alone.