Form 1040 Line-by-Line Reference

This reference maps every Form 1040 line number to its purpose, source data, and calculation method for single W-2 filers.

Personal Information

Field	Description	Source
Your first name and middle initial	Your legal first name	W-2 Box e
Last name	Your legal last name	W-2 Box e
Your social security number	Your full SSN	W-2 Box a (original document)
Filing status	Check “Single”	Always Single for EZFile
Digital assets question	Check “No” (unless crypto held)	User confirmation

Unlike EZFile, you WILL enter your full SSN on the actual tax form. EZFile masks it for privacy during calculation, but the IRS requires the real number to file.

Address Section

Field	Description	Source
Home address	Current mailing address	May differ from W-2 Box f
City, state, ZIP	Current location	User provides

Income Section

Line 1a: Wages, salaries, tips

Value: Sum of all W-2 Box 1 amountsSource: W-2 Box 1 (total taxable federal wages)Note: This is your gross wages MINUS pre-tax deductions (401k, HSA, health insurance). It’s lower than your actual salary if you have pre-tax benefits.Example:

W-2 #1 Box 1: $44,629
W-2 #2 Box 1: $12,500
Line 1a: $57,129

Line 1z: Total wages

Value: Same as Line 1aCalculation: Line 1a + Lines 1b through 1h (if applicable)Note: For single W-2 filers with no dependents, only Line 1a applies.

Line 8: Other income

Value: From Schedule 1, Line 10Source: Unemployment income, gambling winnings, prizes, jury duty payNote: Usually $0 for typical W-2 filers

Line 9: Total income

Value: Line 1z + Line 8Calculation:

Line 9 = Line 1a + Line 8

This is your total income before adjustments.

Adjustments to Income

Line	Field Name	Value	Source
10	Adjustments to income	Schedule 1, Line 26	Student loan interest, educator expenses, etc.
11	Adjusted Gross Income (AGI)	Line 9 - Line 10	This is your AGI

Your AGI (Line 11) is critical—it’s used for credit eligibility, phaseouts, and state returns.

Deductions Section

Line	Field Name	Value	Source
12a	Standard deduction	$15,750 (under 65)<br/>$ 17,750 (65+)	Age-based standard deduction
12b	Charitable deduction	$0	Only if itemizing (rare for this profile)
12c	Schedule 1-A total	From Schedule 1-A	Tips, overtime, car loan, senior deduction
13	Qualified business income	$0	W-2 filers have no QBI
14	Total deductions	12a + 12b + 12c + 13	Sum of all deductions
15	Taxable income	Line 11 - Line 14	Cannot be negative (use $0)

Line 15 (Taxable income) is the number that determines your tax bracket.

Tax Calculation

Line 16: Federal Income Tax

Source: Apply tax brackets to Line 15 (taxable income) 2025 Tax Brackets (Single):

Taxable Income Range	Rate	Tax Calculation
$0 -$ 11,925	10%	taxable_income × 0.10
$11,926 -$ 48,475	12%	$1,192.50 + (taxable_income -$ 11,925) × 0.12
$48,476 -$ 103,350	22%	$5,578.50 + (taxable_income -$ 48,475) × 0.22
$103,351 -$ 197,300	24%	$17,651.00 + (taxable_income -$ 103,350) × 0.24
$197,301 -$ 250,525	32%	$40,099.00 + (taxable_income -$ 197,300) × 0.32
$250,526 -$ 626,350	35%	$57,131.00 + (taxable_income -$ 250,525) × 0.35
Over $626,350	37%	$188,769.75 + (taxable_income -$ 626,350) × 0.37

Example:

Taxable income (Line 15): $35,000
Bracket: $11,926 - $48,475 (12%)
Tax = $1,192.50 + ($35,000 - $11,925) × 0.12
Tax = $1,192.50 + $2,769.00
Line 16: $3,961.50

Additional Tax Lines

Line	Field Name	Value	Source
17	Schedule 2 amount	$0	AMT or excess premium tax credit (rare)
18	Total tax before credits	Line 16 + Line 17	Usually same as Line 16
19	Nonrefundable credits	From Schedule 3	Saver’s Credit if eligible
22	Tax after credits	Line 18 - Line 19	Cannot go below $0
23	Other taxes	$0	Schedule 2 additional taxes
24	Total tax	Line 22 + Line 23	Your final tax liability

Payments Section

Line 25a: Federal tax withheld from W-2s

Value: Sum of all W-2 Box 2 amountsSource: W-2 Box 2 (federal income tax withheld)Example:

W-2 #1 Box 2: $4,200
W-2 #2 Box 2: $1,100
Line 25a: $5,300

Line 25d: Total federal tax withheld

Value: Line 25a + Line 25b + Line 25cNote: For W-2-only filers, this equals Line 25a

Line 27a: Earned Income Credit (EIC)

Eligibility: Single filers with AGI ≤ $19,104 (no children)Value: Based on earned income and AGINote: Must be between 25 and 64 years old

Line 33: Total payments

Value: Line 25d + Line 27a + other creditsThis is the total you’ve already paid (withholding + refundable credits)

Refund or Amount Owed

Refund (Line 34)

If Line 33 > Line 24:Refund = Line 33 - Line 24Direct deposit info:

Line 35b: Bank routing number
Line 35c: Account type (Checking/Savings)
Line 35d: Account number

Amount Owed (Line 37)

If Line 24 > Line 33:Amount owed = Line 24 - Line 33Payment due: April 15, 2026Line 38: Estimated tax penalty (if underpaid)

Supporting Schedules

Schedule 1: Additional Income and Adjustments

When needed: Student loan interest deduction, educator expenses, unemployment income

Line	Field	Value	Source
21	Student loan interest	min($2,500, interest paid)	1098-E form, subject to phaseout
26	Total adjustments	Sum of Part II	Flows to Form 1040 Line 10

Phaseout:

85,000 -

100,000 MAGI

Schedule 1-A: New Deductions (2025)

When needed: Tips, overtime pay, car loan interest, senior deduction

Line	Field	Max Amount	Phaseout
1	Tip income deduction	Actual tips	$75K -$ 100K MAGI
2	Overtime pay deduction	Actual overtime	$75K -$ 100K MAGI
3	Auto loan interest	$10,000	$75K -$ 100K MAGI
4	Senior deduction (65+)	$4,000	$75K -$ 100K MAGI
5	Total	Sum of Lines 1-4	Flows to Form 1040 Line 12c

Form 8880: Saver’s Credit

When needed: AGI ≤ $39,500 AND retirement contributions exist

Line	Field	Value
1	Retirement contributions	W-2 Box 12 (codes D, E, G, AA, BB)
2	Maximum eligible	$2,000
3	Eligible amount	min(Line 1, $2,000)
4	Credit rate	50%, 20%, or 10% (based on AGI)
5	Credit amount	Line 3 × Line 4

AGI Thresholds (Single):

50% credit: AGI ≤ $23,750
20% credit: $23,751 -$ 25,850
10% credit: $25,851 -$ 39,500

Flow: Form 8880 → Schedule 3 Line 4 → Form 1040 Line 19

Key Formulas

AGI (Line 11) = Total Income (Line 9) - Adjustments (Line 10)

Taxable Income (Line 15) = AGI - Total Deductions (Line 14)

Total Tax (Line 24) = Tax from Brackets (Line 16) - Credits (Line 19)

Refund (Line 34) = Payments (Line 33) - Total Tax (Line 24)  [if positive]

Amount Owed (Line 37) = Total Tax (Line 24) - Payments (Line 33)  [if positive]

All line numbers reference the 2025 Form 1040. Line numbers change occasionally—always verify against the current year’s form.

Tax Year 2025

Forms & Fields

Form 1040 Line-by-Line Reference

Personal Information

Address Section

Income Section

Adjustments to Income

Deductions Section

Tax Calculation

Line 16: Federal Income Tax

Additional Tax Lines

Payments Section

Refund or Amount Owed

Refund (Line 34)

Amount Owed (Line 37)

Supporting Schedules

Schedule 1: Additional Income and Adjustments

Schedule 1-A: New Deductions (2025)

Form 8880: Saver’s Credit

Key Formulas

Build docs developers (and LLMs) love

Tax Year 2025

Forms & Fields

​Personal Information

​Address Section

​Income Section

​Adjustments to Income

​Deductions Section

​Tax Calculation

​Line 16: Federal Income Tax

​Additional Tax Lines

​Payments Section

​Refund or Amount Owed

Refund (Line 34)

Amount Owed (Line 37)

​Supporting Schedules

​Schedule 1: Additional Income and Adjustments

​Schedule 1-A: New Deductions (2025)

​Form 8880: Saver’s Credit

​Key Formulas

Build docs developers (and LLMs) love

Personal Information

Address Section

Income Section

Adjustments to Income

Deductions Section

Tax Calculation

Line 16: Federal Income Tax

Additional Tax Lines

Payments Section

Refund or Amount Owed

Supporting Schedules

Schedule 1: Additional Income and Adjustments

Schedule 1-A: New Deductions (2025)

Form 8880: Saver’s Credit

Key Formulas