How a Louisiana paycheck works
Louisiana rebuilt its income tax from 2025. The old three-band schedule and the deduction for federal income tax paid are gone, replaced by a single flat rate and a large standard deduction that is indexed each year. Withholding follows a one-line formula: annualise the wage, subtract the standard deduction claimed on the state certificate, and apply the withholding rate.
Federal income tax withholding
Federal withholding annualises the wage, subtracts the standard deduction for the filing status on Form W-4 Step 1, applies the graduated schedule for that status, and deducts the dependent credit from Step 3. This page models a W-4 with Steps 2 and 4 blank: one job, no spouse income, no other income, no extra withholding. Past the income limit the dependent credit tapers by a set amount for every thousand dollars of excess.
Social Security and Medicare
Social Security takes a flat rate on wages up to an annual ceiling that moves each year, so it stops partway through the year for a high earner. Medicare applies to every dollar, and above a fixed threshold the employer withholds the Additional Medicare tax on the excess, unmatched and regardless of filing status.
The withholding rate is above the tax rate on purpose
Louisiana withholds at a rate slightly higher than the statutory flat rate. The Department of Revenue describes this as a cushion: because the formula ignores everything except the standard deduction, a small deliberate over-withholding keeps most employees out of a balance due at filing time. It means the state line on your payslip is marginally larger than the flat rate alone would produce.
Form R-1300 (L-4) and the standard deduction
The state certificate asks how many exemptions you claim, and the answer selects which of three formulas the employer uses. Claiming none means no standard deduction at all and the rate applies to the whole wage. Claiming one gives the single standard deduction. Claiming two gives the doubled amount, which is also what married couples filing jointly, qualifying surviving spouses and heads of household use. Dependants no longer feature in the withholding formula after the reform.
Local income tax
No Louisiana parish or municipality taxes wages. New Orleans and Baton Rouge have the same payroll deductions as the rest of the state.
What the employer pays on top
The employer matches Social Security and Medicare and pays federal unemployment tax at its net rate. Louisiana unemployment insurance is an employer contribution at an experience-rated percentage. There is no employee-side state levy.
What this calculator assumes
The figure models a salaried employee paid evenly across the year with a standard Form W-4 and state certificate, and no pre-tax deductions. It leaves out:
- Pre-tax contributions such as a 401(k), health premiums, HSA or flexible spending accounts.
- Extra withholding requested on the federal or state certificate, and the W-4 Step 2 and Step 4 adjustments.
- Bonuses and other supplemental wages, which may be withheld at a flat supplemental rate.
- Employer-side state unemployment insurance, which is priced per employer, and any federal unemployment credit reduction.
- Employees outside the normal Social Security system, such as some public-sector staff and certain visa holders.
Withholding versus your final tax bill
Withholding is a prepayment. The federal and state returns replace these assumptions with your real situation: itemised deductions, other income, and credits payroll knows nothing about. One job usually produces a refund; two jobs or a working spouse often produce a balance due.