Flexible Spending Account (FSA) Calculator
A flexible spending account (FSA) is an employer-sponsored benefit that lets you set aside a portion of your pre-tax salary to pay for qualified medical expenses, reducing your taxable income and lowering your federal income tax, state income tax (in most states), and FICA taxes on the contributed amount. For 2025, the IRS limits healthcare FSA contributions to $3,300 per employee, and the dependent care FSA limit is $5,000 per household ($2,500 if married filing separately). Healthcare FSA funds can pay for medical, dental, and vision expenses not covered by insurance, including copayments, deductibles, prescription drugs, and certain over-the-counter items. Dependent care FSA funds can pay for qualifying child or adult day care expenses that allow you and your spouse to work or look for work. Unlike health savings accounts (HSAs), FSAs are generally subject to a use-it-or-lose-it rule: funds not spent by the plan year deadline are forfeited, although employers may offer a grace period of up to 2.5 months or allow a limited rollover of up to $660 (2025 IRS limit). This calculator shows the total tax savings from your FSA contributions by applying the reduction to your marginal federal rate, applicable state rate, and FICA rates, as well as the effective after-tax cost of your elected contribution amount.
Contributing $3,300 to a Healthcare FSA at a 22% federal tax rate and 5% state rate saves you -- in taxes per year.
How FSA tax savings are calculated
FSA contributions are deducted from your paycheck before taxes are calculated. This means they reduce your taxable income, which saves you federal income tax at your marginal rate. They also reduce your Social Security and Medicare wages, saving you FICA taxes. State income taxes are also saved in most states that have an income tax.
Total contribution = Healthcare FSA + Dependent Care FSA
FICA savings = total contribution * 0.0765
Federal tax savings = total contribution * (federal rate / 100)
State tax savings = total contribution * (state rate / 100)
Total savings = FICA + federal + state
Effective cost = contribution - total savings
Maximizing FSA benefits
The key to getting the most value from an FSA is accurate estimation of your qualified expenses. Healthcare costs are often predictable if you take regular medications or have planned dental or vision work. Dependent Care FSAs are appropriate if you pay for daycare or after-school care. The use-it-or-lose-it rule means over-contributing costs you money, so be conservative.
Ask your HR department whether your employer offers a carryover or grace period. A $660 carryover or 2.5-month grace period gives you flexibility if you slightly over-estimate expenses. Keep all receipts and submit claims promptly so you know exactly how much you have spent and how much is left to reimburse.
FSAs work best alongside an HSA (if you have a high-deductible health plan) or as the primary tax-advantaged account for healthcare costs. Combined with careful budgeting, an FSA can reduce your effective healthcare costs by 20 to 40 percent after tax savings.
FSA calculator: frequently asked questions
What is the difference between a Healthcare FSA and a Dependent Care FSA?
A Healthcare FSA lets you set aside pre-tax money to pay for qualified medical, dental, and vision expenses. A Dependent Care FSA lets you set aside pre-tax money to pay for childcare or care for a dependent adult while you work. They have different annual limits: Healthcare FSA is $3,300 in 2025, and Dependent Care FSA is $5,000 per household. They are separate accounts and you can contribute to both.
What happens to money I don't spend in my FSA?
Under the use-it-or-lose-it rule, any FSA funds remaining at the end of the calendar year are forfeited to your employer. However, employers may offer either a carryover up to $660 (indexed annually) to the next year, or a grace period of up to 2.5 months into the next year. Ask your employer which option they provide. To avoid losing money, estimate your medical expenses conservatively and contribute only what you expect to use.
Can I have both an FSA and an HSA?
You cannot have a Healthcare FSA and an HSA at the same time because they serve the same purpose. However, you can have a Limited-Purpose FSA (covering only dental and vision) alongside an HSA. If you have both a Healthcare FSA and want to save more, you would need to contribute to the Healthcare FSA instead of an HSA. Dependent Care FSAs are separate and can be used with an HSA.
What tax advantages does an FSA provide?
FSA contributions are made with pre-tax dollars, which reduces your taxable income and federal income tax. You also avoid paying FICA taxes (Social Security and Medicare taxes, 7.65% combined) on FSA contributions. If you contribute $3,300 to a Healthcare FSA, you save roughly $825 in federal income tax (at 22% rate) plus $252 in FICA taxes, for total savings of about $1,077. State income tax savings depend on your state.
What counts as a qualified medical expense for an FSA?
Qualified medical expenses include doctor visits, prescriptions, dental care, vision care, medical equipment, and certain over-the-counter medications. However, expenses for cosmetic procedures, general wellness, or toiletries do not qualify. The IRS maintains a detailed list of eligible expenses in Publication 969. Keep all receipts because your FSA provider may ask for proof of qualified expenses.
Can I withdraw money from my FSA before the year ends?
No, FSAs are not savings accounts. You can only reimburse yourself for qualified expenses you have already paid. You cannot make a withdrawal simply to access the money. This is different from an HSA, where you can withdraw for any reason, though non-qualified withdrawals incur a 20% penalty plus taxes. FSAs are designed for specific, planned expenses.
Official sources
- IRS Publication 969: Health Savings Accounts and Other Tax-Favored Health Plans.
- IRS Rev Proc 2024-40: 2025 FSA and HSA limits.
- IRC Section 129: Dependent Care FSA Rules.
Reviewed by the CalculatorHub team, edited by James Graham, 13 June 2026. See our methodology. General information, not financial advice.