Filing Status: The Single Choice That Moves Your Tax Bill Most
Filing status is a single dropdown, and it moves your tax bill more than almost any other input. It sets your standard deduction, it sets the width of every bracket, and in many states it changes the state schedule too.
At $83,200 of income in California, the spread between the best and worst status available to a given person is $5,896 a year.
| Status | Federal deduction | Federal tax | CA state tax | Net pay |
|---|---|---|---|---|
| Single | $16,100 | $9,474 | $3,646 | $63,716 |
| Married filing jointly | $32,200 | $5,624 | $1,599 | $69,612 |
| Married filing separately | $16,100 | $9,474 | $3,646 | $63,716 |
| Head of household | $24,150 | $6,732 | $1,599 | $68,504 |
Single
The default if you are unmarried and do not support a dependent. Standard deduction $16,100, and the narrowest brackets of the four.
Married filing jointly
Both spouses report on one return. The standard deduction doubles to $32,200 and every federal bracket threshold doubles, which is why it is almost always the cheapest option for a married couple.
The important caveat for a calculator: those doubled brackets apply to the couple's combined income. If you enter one salary and select joint, you are seeing the tax on a household where one person earns and the other does not. Add a second income and the number rises. That single-earner case is where the status is worth the most — the so-called marriage bonus.
Two similar incomes get much less benefit, because the combined figure climbs back up the doubled brackets at roughly the same rate.
Married filing separately
Each spouse files their own return. Brackets and the standard deduction match single filers, and it disqualifies you from several credits. It is usually more expensive — at $83,200 here it costs -$5,896 compared with filing jointly.
It exists for specific situations rather than optimisation: separating liability from a spouse's tax position, income-driven student loan repayment calculations, or a divorce in progress. If none of those apply, joint is nearly always better.
Head of household
The most commonly missed status. It requires all three: you are unmarried on the last day of the year, you paid more than half the cost of maintaining your home, and a qualifying person — usually a child or dependent relative — lived with you for more than half the year.
It sits between single and joint: a $24,150 standard deduction and wider low brackets. At this income it is worth $4,788 a year over filing single. A single parent filing as single rather than head of household is simply overpaying.
State treatment varies
States do not follow the federal pattern uniformly. Flat-tax states like Pennsylvania and Illinois charge the same rate regardless of status, so only the deduction can differ. Others double their brackets for joint filers exactly as the federal system does. California is in the second group, which is why the state column in the table above moves so much.
A handful of states publish a distinct head-of-household schedule; most apply either their single or their joint table. This calculator uses the verified schedule where one exists and otherwise falls back to the single-filer table, which never understates what is owed.
Choosing
For most people the status is a fact, not a choice — you are married or you are not, you support a dependent or you do not. The decision only really exists for married couples weighing joint against separate, and for anyone who might qualify as head of household without realising it.
Both are worth testing rather than assuming. Every salary page has the filing status selector, and the numbers update immediately — try it on $40/hr in California.