What will my W2 wages be?
Type your gross pay for the year and your pre-tax deductions. The answer is what the wage boxes of your Form W-2 will show, and why box 1 is lower than your salary.
- Box 1: wages, tips, other compensation
- $66,000.00
On $75,000.00 of gross pay, box 1 of your W-2 shows $66,000.00, and boxes 3 and 5 show $72,000.00 and $72,000.00.
- Box 3: Social Security wages
- $72,000.00
- Box 4: Social Security tax withheld
- $4,464.00
- Box 5: Medicare wages and tips
- $72,000.00
- Box 6: Medicare tax withheld
- $1,044.00
- Box 12: retirement deferrals
- $6,000.00
- Left out of every wage box
- $3,000.00
- Box 5 minus box 1
- $6,000.00
Box 1: wages, tips, other compensation: $66,000.00. On $75,000.00 of gross pay, box 1 of your W-2 shows $66,000.00, and boxes 3 and 5 show $72,000.00 and $72,000.00.
Where does gross pay go on the W-2?
The results are estimates for information only. They are not financial, tax, or legal advice. Check the numbers with your lender or a qualified professional before you decide. Terms of use
How to calculate
Works out the wage boxes of your Form W-2 (box 1 taxable wages, boxes 3 and 5 Social Security and Medicare wages, boxes 4 and 6 tax withheld) from gross pay and pre-tax deductions.
Example with the default inputs (Gross pay for the year $75,000.00, Pre-tax retirement deferrals $6,000.00, Section 125 deductions $3,000.00, Pre-tax commuter benefits $0.00, W-2 year 2,026): On $75,000.00 of gross pay, box 1 of your W-2 shows $66,000.00, and boxes 3 and 5 show $72,000.00 and $72,000.00.
Method: Box 5 = gross − section 125 − commuter benefits. Box 1 = box 5 − pre-tax retirement deferrals. Box 3 = the lesser of box 5 and the Social Security wage base ($184,500 in 2026). Box 4 = 6.2% × box 3. Box 6 = 1.45% × box 5 + 0.9% × (box 5 − $200,000, if above 0). Box 12 = the deferrals.
- One employer for the whole year. With two jobs, each W-2 has its own wage base and $200,000 withholding threshold.
- Roth 401(k) contributions, after-tax deductions, and wage garnishments do not change any wage box.
- Group-term life insurance over $50,000, taxable fringe benefits, dependent care benefits over $5,000, and commuter benefits over the monthly limit add to the boxes and are not included.
- Box 2 (federal income tax withheld) depends on your Form W-4 and pay periods: use the federal withholding calculator.
Worked examples
Each example is checked against the calculator on every build.
- Gross pay for the year $75,000.00, Pre-tax retirement deferrals $6,000.00, Section 125 deductions $3,000.00, Pre-tax commuter benefits $1,200.00 gives Box 1: wages, tips, other compensation $64,800.00, Box 3: Social Security wages $70,800.00, Box 4: Social Security tax withheld $4,389.60, Box 5: Medicare wages and tips $70,800.00, Box 6: Medicare tax withheld $1,026.60, Box 12: retirement deferrals $6,000.00.Source: IRS 401(k) plan overview (deferrals stay in Social Security and Medicare wages); IRS cafeteria plan FAQ and Pub 15-B Table 2-1 (section 125 and commuter benefits excluded from all three)
- Gross pay for the year $250,000.00, Pre-tax retirement deferrals $24,500.00, Section 125 deductions $0.00, Pre-tax commuter benefits $0.00 gives Box 1: wages, tips, other compensation $225,500.00, Box 3: Social Security wages $184,500.00, Box 4: Social Security tax withheld $11,439.00, Box 5: Medicare wages and tips $250,000.00, Box 6: Medicare tax withheld $4,075.00.Source: Pub 15 (2026): Social Security wage base $184,500; Additional Medicare Tax withheld at 0.9% over $200,000
- Gross pay for the year $40,000.00, Pre-tax retirement deferrals $0.00, Section 125 deductions $0.00, Pre-tax commuter benefits $0.00 gives Box 1: wages, tips, other compensation $40,000.00, Box 3: Social Security wages $40,000.00, Box 4: Social Security tax withheld $2,480.00, Box 6: Medicare tax withheld $580.00.
How it works
All arithmetic is exact on the amounts you type.
- Box 5, Medicare wages = gross pay − section 125 deductions − pre-tax commuter benefits.
- Box 1, wages = box 5 − pre-tax retirement deferrals (traditional 401(k), 403(b), 457(b), SIMPLE IRA).
- Box 3, Social Security wages = the lesser of box 5 and the Social Security wage base ($184,500 for 2026).
- Box 4, Social Security tax = 6.2% × box 3.
- Box 6, Medicare tax = 1.45% × box 5 + 0.9% × (box 5 − $200,000), the second part only when box 5 is over $200,000.
- Box 12 = the retirement deferrals (code D for a 401(k), E for a 403(b), G for a 457(b), S for a SIMPLE IRA).
Commuter benefits can be at most $8,160 for the year: $340 a month for transit passes or vanpools and $340 a month for qualified parking (2026, Publication 15-B); amounts over the limit are taxable wages and are not covered. If section 125 and commuter deductions are more than gross pay, or all pre-tax deductions together are, there is no answer. Amounts are not rounded; your W-2 shows them to the cent.
When the data is out of date
The wage base and rates are for 2026. A later year uses the 2026 wage base and says so above the result; the wage base usually rises each year.
Worked examples by hand
$75,000 gross, $6,000 to a 401(k), $3,000 of section 125 deductions, $1,200 of transit passes. Box 5 = 75,000 − 3,000 − 1,200 = $70,800. Box 1 = 70,800 − 6,000 = $64,800. Box 3 = $70,800. Box 4 = 6.2% × 70,800 = $4,389.60. Box 6 = 1.45% × 70,800 = $1,026.60.
$250,000 gross, $24,500 to a 401(k). Box 5 = $250,000; box 1 = $225,500; box 3 = $184,500 (the wage base); box 4 = $11,439; box 6 = 1.45% × 250,000 + 0.9% × 50,000 = 3,625 + 450 = $4,075.
Other questions people ask
Why is box 1 of my W-2 lower than my salary?
Box 1 leaves out pre-tax deductions: traditional 401(k), 403(b), and 457(b) deferrals, section 125 cafeteria plan deductions (health premiums, FSA, HSA through payroll), and pre-tax commuter benefits. Those amounts are not taxed as income this year.
Why are boxes 3 and 5 higher than box 1?
Retirement deferrals are excluded from income tax but still count as wages for Social Security and Medicare (IRS, 401(k) plan overview). So box 3 and box 5 include them; box 1 does not. Section 125 and commuter deductions are left out of all three.
What is the most box 3 can show in 2026?
$184,500, the 2026 Social Security wage base (IRS Publication 15). Box 4 is then at most 6.2% of it, $11,439. Box 5 has no limit.
Why is box 6 more than 1.45% of box 5?
Your employer must withhold an extra 0.9% Additional Medicare Tax on wages over $200,000 in the year, whatever your filing status. Box 6 includes it.
Can I use my last pay stub to estimate my W-2?
Yes. Use the year-to-date gross pay and year-to-date pre-tax deductions from your last pay stub of the year. Box 1 should match year-to-date taxable wages on the stub, if your payroll shows it.
Do Roth 401(k) contributions lower box 1?
No. Roth contributions are taken after tax, so they stay in boxes 1, 3, and 5. Your employer shows them in box 12 with code AA.