United States version
How it works
Compare explicitly eligible contribution scenarios, requiring confirmed annual limits and compatible plan coverage rather than outdated statutory defaults.
This is the United States planning view, with monetary inputs and outputs in USD. A currency label does not establish that a tax rate, construction price, coverage rule or legal limit has been verified locally. The inputs and limitations below describe the actual scope.
Input query strings and outputs
Use an input name in this page’s URL as ?name=value, and join additional inputs with &. Portable shared links may instead use the compact ?ac= state parameter.
Input query strings
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?hsaContribution=Eligible HSA contribution under considerationMoney · Required · Default: 3,000
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?confirmedHsaLimit=Confirmed applicable HSA annual limitMoney · Required · Default: 0
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?fsaContribution=FSA contribution under considerationMoney · Required · Default: 2,000
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?confirmedFsaLimit=Confirmed applicable FSA annual limitMoney · Required · Default: 0
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?eligibleSpending=Expected eligible expenses available to this FSAMoney · Required · Default: 1,800
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?confirmedCarryover=Plan-confirmed permitted FSA carryoverMoney · Required · Default: 0
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?incomeTaxRate=Applicable marginal income tax assumptionPercentage · Required · Default: 22
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?payrollTaxRate=Applicable payroll tax saving on these salary reductionsPercentage · Required · Default: 7.65
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?eligible=I have confirmed HSA eligibility and compatible FSA coverageTrue or false · Optional · Default: false
Outputs
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hsaTaxSavingIllustrative HSA tax savingCurrency · Primary output · Currency: USD
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fsaTaxSavingIllustrative FSA tax savingCurrency · Currency: USD
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fsaUnusedFSA amount not used for entered expensesCurrency · Currency: USD
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fsaForfeitureModeled forfeiture after permitted carryoverCurrency · Currency: USD
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fsaNetBenefitIllustrative FSA tax saving minus forfeitureCurrency · Currency: USD
Formula
illustrative tax saving = eligible salary-reduction contribution × entered applicable tax rates.
Calculations retain numeric precision internally. Displayed values are rounded for readability. Quantities that must be purchased as whole units are rounded up only where the formula explicitly requires it.
Read the inputs before calculating
- Eligible HSA contribution under consideration: Enter the quantity described by the label.
- Confirmed applicable HSA annual limit: Enter the quantity described by the label.
- FSA contribution under consideration: Enter the quantity described by the label.
- Confirmed applicable FSA annual limit: Enter the quantity described by the label.
- Expected eligible expenses available to this FSA: Enter the quantity described by the label.
- Plan-confirmed permitted FSA carryover: Enter the quantity described by the label.
- Applicable marginal income tax assumption: Enter the quantity described by the label.
- Applicable payroll tax saving on these salary reductions: Enter the quantity described by the label.
- I have confirmed HSA eligibility and compatible FSA coverage: Enter the quantity described by the label. Leave this unconfirmed until you have actually checked the required condition.
Reproducible worked example
The following is a fictional arithmetic example, not a local quote, a verified claimant or a market forecast. Its values are included so the formula can be checked. The form does not automatically confirm any verification checkbox.
I have confirmed HSA eligibility and compatible FSA coverage: assumed confirmed solely for this fictional demonstration
The entered 3,000 and 2,000 limits are deliberately synthetic plan inputs, not published statutory limits.
| Input | Example value |
|---|---|
| Eligible HSA contribution under consideration | 3,000 |
| Confirmed applicable HSA annual limit | 3,000 |
| FSA contribution under consideration | 2,000 |
| Confirmed applicable FSA annual limit | 2,000 |
| Expected eligible expenses available to this FSA | 1,800 |
| Plan-confirmed permitted FSA carryover | 0 |
| Applicable marginal income tax assumption | 22 |
| Applicable payroll tax saving on these salary reductions | 7.65 |
| I have confirmed HSA eligibility and compatible FSA coverage | true |
| Output | Calculated result |
|---|---|
| Illustrative HSA tax saving | USD 889.5 |
| Illustrative FSA tax saving | USD 593 |
| FSA amount not used for entered expenses | USD 200 |
| Modeled forfeiture after permitted carryover | USD 200 |
| Illustrative FSA tax saving minus forfeiture | USD 393 |
Interpreting a changed assumption
Start with one complete scenario and change only one input when diagnosing a difference. Recheck units, the period of every rate, whether an amount is recurring or one-off, and whether a cost is already included elsewhere. A larger calculated benefit is not evidence that an assumption is more likely to occur.
Limitations
- This uses entered contract assumptions. It is not lending approval, personalized financial advice or a substitute for the actual fee schedule and local credit/tax rules.
- The payroll-tax assumption applies only to an eligible salary-reduction arrangement; direct HSA contributions generally require different treatment. Employer contributions, catch-up, partial-year eligibility, grace periods, state conformity and tax-free reimbursements need separate verification.
Frequently asked questions
What does this HSA Versus FSA Planning result represent?
Compare explicitly eligible contribution scenarios, requiring confirmed annual limits and compatible plan coverage rather than outdated statutory defaults. It applies the displayed formula to your inputs; it does not infer omitted facts.
Are the starting amounts verified United States prices or legal rules?
No. Numeric defaults are illustrative unless an input or dated reference explicitly identifies a researched component. Currency is USD; local quotes, eligibility and unsupported rules must be entered and verified separately.
What must I check before relying on the result?
This uses entered contract assumptions. It is not lending approval, personalized financial advice or a substitute for the actual fee schedule and local credit/tax rules.
Can I compare or share different assumptions?
Change one assumption at a time and use the browser-local project or share controls. A shared URL contains the encoded input values; do not include information you do not wish to disclose.
Sources and reference scope
- CFPB loan-estimate explanation — retrieved 2026-09-24. US cost components; the general amortization formula is stated separately.
- CFPB comparing borrowing costs — retrieved 2026-09-24. Distinguishing interest, principal, fees and timing in a comparison.
These references support only their stated scope. They are not evidence that every local rule or price needed by the master expansion has been loaded.