How a Kansas paycheck works
Kansas withholding annualises the wage, subtracts a withholding allowance amount built from personal exemptions, and runs the remainder through a short rate table with a nil band at the bottom and two rates above it. Which rate table applies is decided by a single question on Form K-4, and it is not the same question the federal Form W-4 asks.
Federal income tax withholding
Federal withholding annualises the wage, subtracts the standard deduction that matches 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 left blank: one job, no spouse income, no other income, no extra withholding. Above the income limit for the status, the dependent credit tapers by a set amount for every thousand dollars of excess rather than disappearing at a cliff.
Social Security and Medicare
Social Security applies a flat rate to wages up to an annual ceiling that is re-indexed each year, so it stops partway through the year for a high earner. Medicare applies to every dollar, and above a fixed wage threshold the employer withholds the Additional Medicare tax on the excess, with no employer match and no regard for filing status.
Form K-4 asks about your spouse, not your filing status
The first line of Form K-4 asks you to pick an allowance rate, single or joint, and the instruction is explicit that it may differ from the status on your federal W-4. A single filer picks single. A married employee whose spouse has income also picks single. Only a married employee whose spouse has no income picks joint.
That choice does two things at once: it doubles the exemption amount subtracted from your pay, and it moves you onto a second rate table whose nil band and upper band are both wider. So on this page, selecting married on its own changes nothing in the Kansas line. It is the spouse question that moves it, and it can move it by a lot.
The logic is the familiar one. If both spouses claimed the joint amount on their own payroll, the couple would subtract the exemption twice and end the year owing money. If you never file a K-4 at all, your employer withholds at the single rate with no exemption, which is the largest amount the formula produces.
Head of household
Kansas does not give head of household its own rate table. It uses the single table, but the K-4 worksheet lets a head of household claim an extra allowance on top of the personal exemption, so the amount subtracted from your pay is larger than a single filer's while the rate table stays the same.
Dependants
Each dependant you claim on the K-4 worksheet adds a further fixed amount to the withholding allowance. Like the head of household allowance, it comes off income rather than off tax, so it is worth the marginal rate times the allowance. The worksheet warns you not to claim a dependant your spouse has already claimed on their own K-4.
Rounding
Kansas is unusual in saying withholding computed by the percentage formula may be rounded to the nearest whole dollar rather than must be. The wage bracket tables an employer can use instead are pre-rounded. This page keeps the cent, since that is what the formula itself produces, so a payslip from an employer who rounds may differ by a few cents.
Local income tax
No Kansas county or city taxes wages. Wichita, Overland Park and Topeka all have the same payroll deductions as anywhere else in the state.
What the employer pays on top
The employer matches Social Security and Medicare and pays federal unemployment tax at its net rate. Kansas unemployment insurance is charged to the employer at a rate set from its own claims record on a state wage base, so it is left out. There is no employee-side state levy in Kansas: no disability insurance, no paid family leave premium.
What this calculator assumes
The figure models a salaried employee paid evenly across the year with a standard Form W-4 and Form K-4, and no pre-tax deductions. It leaves out:
- Pre-tax contributions such as a 401(k), health premiums, HSA or flexible spending accounts, which reduce the wages subject to income tax and often to FICA.
- 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 annual returns, federal and state, replace these standard assumptions with your real situation: itemised deductions, other income, and credits payroll knows nothing about. One job usually produces a refund; two jobs, a working spouse or investment income often produce a balance due.