Your salary before any taxes or deductions. Find it on your pay stub, offer letter, or W-2 box 1.

Affects your tax strategy. Texas, Florida, Washington, Nevada, Wyoming, South Dakota, Alaska, Tennessee, and New Hampshire have no state income tax.

Used to determine catch-up contribution eligibility. Age 50+ gets higher 401(k) and IRA limits. Age 55+ gets higher HSA limits. Ages 60-63 get a special higher 401(k) catch-up.

Single if you file taxes alone. Married filing jointly if you are married and file together — this affects Roth IRA income limits and tax brackets.