How a Washington paycheck works
Washington does not tax personal income, and no city taxes wages. It does, however, run two statewide social insurance programmes that are funded partly or wholly by the employee, so a Washington payslip is not federal-only. Paid Family and Medical Leave takes a share of a premium charged on wages up to the Social Security cap, and the WA Cares Fund, the state's long-term care programme, takes a flat premium from every dollar of wages with no cap at all. Both appear as lines in the result below, alongside federal income tax withholding, Social Security and Medicare.
Federal income tax withholding
Federal withholding starts from the annual wage, removes the standard deduction that matches the filing status on Form W-4 Step 1, applies the graduated schedule for that status, and then deducts the dependent credit from Step 3. The figures here assume a Form W-4 filled in with Steps 2 and 4 empty, which describes a single job with no working spouse, no other income and no additional withholding requested.
Above the income limit for the filing status the dependent credit tapers rather than disappearing: a set amount is removed for every thousand dollars over the line. The calculator models the taper, so the curve stays smooth around the threshold.
Social Security and Medicare
The two FICA contributions behave differently. Social Security applies a flat rate to wages up to a yearly ceiling that moves with national wage growth, so a high earner stops paying it partway through the year. Medicare applies to every dollar. Above a fixed wage threshold the employer withholds the Additional Medicare tax on top, with no employer match and no regard for filing status.
Paid Family and Medical Leave
The programme charges a single premium on wages up to the same annual cap the Social Security tax uses. The employer withholds the employee's share of that premium and adds its own share on top, although the smallest employers are exempt from the employer part. Because the state publishes a premium rate and a separate employee share, this calculator applies the two in sequence exactly as the Employment Security Department describes, rather than collapsing them into a single rounded rate.
WA Cares long-term care premium
WA Cares is funded entirely by employees. The premium is a flat percentage of gross wages with no wage ceiling, so unlike Social Security it does not stop partway through the year for a high earner, and it makes the effective deduction rate flatter at the top than in a state with no such programme. Some workers hold an approved exemption; the calculator assumes you do not.
What the employer pays on top
The employer matches Social Security and Medicare and pays federal unemployment tax at its net rate. It also pays its share of the Paid Leave premium and Washington unemployment insurance at an experience-rated percentage, and most businesses pay the state Business and Occupation tax on gross receipts. Those are employer costs that vary by company, so they are not shown as lines.
What this calculator assumes
The figure models a salaried employee paid evenly across the year on a standard Form W-4 with no pre-tax deductions. It leaves out:
- Pre-tax contributions such as a 401(k), health premiums, HSA or a flexible spending account, which lower the wages subject to income tax and often to FICA.
- Extra withholding requested on the W-4, and the Step 2 and Step 4 adjustments for a second job, a working spouse or other income.
- Bonuses and other supplemental wages, which employers may withhold at a flat supplemental rate instead.
- 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, not the tax itself. The annual return replaces the standard assumptions with your real situation: itemised deductions when they beat the standard one, investment or freelance income, and credits the payroll system knows nothing about. Employees with one job usually see a refund; two jobs, a working spouse or significant investment income often produce a balance due. Use this page for monthly budgeting and a full return estimate for the year.