Tool · Schedule SE (Form 1040)

Schedule SE Estimator

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This is education, not tax advice. I'm not a CPA or EA. State taxes are not covered.

Schedule SE (Form 1040) — the short form, in the reading Article 2 verified: the form text read on the 2025 form and cross-checked on the 2026 draft (posted May 21, 2026); the $184,500 ceiling at line 7 is the figure preprinted on the 2026 draft. If a line or the ceiling changes on the final form, this page is updated in place with a dated note at the foot of the page.

Last checked: 2026-10-11
Reads: Schedule SE (Form 1040) · Instructions for Schedule SE
Core line: Schedule SE, line 12
Changes: Update log (1)

Enter one number — the net profit Schedule C figured — and the page runs the short form’s own build on it: the profit shrunk to 92.35 percent, stopped at the $400 gate, measured against the Social Security ceiling that any W-2 wages shrink, taxed at one capped rate and one uncapped rate, and halved at the end. The page outputs the form’s figures — the line 12 tax and the line 13 deductible part — never a recommendation, and never an amount of tax saved.

JavaScript is off, so nothing is figured for you — the short form’s arithmetic stands below in full, worked by hand: net profit × 92.35 percent at line 4a; if line 4c is under $400, stop — no tax is owed. Otherwise, 12.4 percent of the smaller of line 6 or the remaining ceiling at line 10, plus 2.9 percent of line 6 at line 11; the sum is the tax at line 12, and one-half of it is the deductible part at line 13.

Schedule SE (Form 1040) — short formProfit → line 12

Net profit — the amount line 2 reads in, from Schedule C, line 31.

Combine lines 1a, 1b, and 2. This page figures one nonfarm business with no Schedule K-1 amounts — the path Article 2 walks — so line 3 is the line 2 amount.

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Multiply line 3 by 92.35% (0.9235), when line 3 is over $0. From here on, the form works with 92.35 percent of the profit.

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Add lines 4a and 4b. Line 4b is where optional methods would enter; none are figured on this page, so line 4c is line 4a. The gate: if line 4c is less than $400, stop — no self-employment tax is owed on that amount.

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Net earnings from self-employment — line 4c + line 5b. Line 5 is the church-employee section; nothing on it is figured here, so line 6 is line 4c.

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The ceiling, preprinted on the 2026 draft form: the maximum amount of combined wages and self-employment earnings subject to the Social Security part of the tax.

$184,500

Total Social Security wages and tips (optional). Lines 8a–8d collect a W-2 job’s Social Security wages and the related amounts the form lists, and reach line 9 as one total. Enter the W-2 amount here; leave it at zero if there was no W-2 job in the year.

Remaining ceiling — subtract the line 8 total from line 7. If the total is the larger amount, line 9 is zero, not less.

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Multiply the smaller of line 6 or line 9 by 12.4% — the Social Security part, the one rate on this form that runs against a capped base.

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Multiply line 6 by 2.9% — the Medicare part. No ceiling is compared on this line.

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Self-employment tax — add lines 10 and 11. Enters Schedule 2, line 4.

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Deductible part of self-employment tax — one-half of line 12, entered on Schedule 1, line 15. It is an income deduction; it does not reduce the line 12 tax.

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The reading behind this page is Article 2, which walks the same lines on paper, with its own worked example. This page figures the short form only, on that reading: one nonfarm business, the amount from Schedule C, line 31. It does not figure your profit — by the time line 2 reads a number in, Schedule C has already done that work.

Optional methods are not figured. Line 4b, and Part II of the form (Optional Methods To Figure Net Earnings) behind it, are printed on the form but are not read here; this page runs the path with no optional methods, the only path Article 2 walks.

Church employee income is not figured. It is the one printed exception that continues past the $400 stop, to line 5 — and it is not a line this page computes.

The 0.9 percent Additional Medicare Tax is not figured here. When that tax applies, it is figured on Form 8959, which is not read on this page; the uncapped 2.9 percent on line 11 is the only Medicare rate this form prints.

Not an estimated-tax figure. Line 12 is a full-year tax on a return. How a tax like this is spread across the year is Form 1040-ES and Publication 505 — the worksheet Article 1 reads, also here as the 2026 Estimated Tax Worksheet.

Sources

7 claims

Every claim above traces to a document, a tax year, a line, and the date it was checked.

1

Line 2 reads net profit from Schedule C line 31 (plus Schedule K-1 box 14, code A amounts where they apply); line 3 combines lines 1a, 1b, and 2

DOC
Schedule SE (Form 1040)

YEAR
Form text 2025; 2026 draft posted 2026-05-21

LINE
Lines 2, 3

CHECKED
2026-10-06
2

Line 4a: line 3 × 92.35% (0.9235) when line 3 is over $0; line 4c under $400 — stop, no SE tax (the church-employee exception continues to line 5); the filing trigger is line 4c of $400 or more

DOC
Schedule SE form text; Instructions for Schedule SE

YEAR
2025, latest posted at check date; $400 wording confirmed kept on the 2026 draft

LINE
Lines 4a–4c; i1040sse “Who Must File”

CHECKED
2026-10-06
3

Line 6: net earnings from self-employment = line 4c + line 5b

DOC
Schedule SE form text

YEAR
2025; structure cross-checked on the 2026 draft

LINE
Line 6

CHECKED
2026-10-06
4

Line 7: the maximum combined wages and self-employment earnings subject to Social Security tax, preprinted $184,500 for 2026; line 9 = line 7 − line 8d (W-2 Social Security wages and related amounts, lines 8a–8d)

DOC
Schedule SE (2026 draft)

YEAR
2026 — IRS draft as of 2026-10-06

LINE
Lines 7, 8a–8d, 9

CHECKED
2026-10-06
5

Line 10: smaller of line 6 or line 9, × 12.4%; line 11: line 6 × 2.9%, no cap

DOC
Schedule SE form text

YEAR
2025; cross-checked on the 2026 draft

LINE
Lines 10, 11

CHECKED
2026-10-06
6

Line 12: self-employment tax, reported on Schedule 2 (Form 1040) line 4; Schedule 2 line 21 then feeds Form 1040 line 23

DOC
Schedule SE (2026 draft); Schedule 2 (2026 draft)

YEAR
2026 — IRS draft as of 2026-10-06

LINE
Schedule SE line 12; Schedule 2 lines 4, 21

CHECKED
2026-10-06
7

Line 13: one-half of line 12, reported on Schedule 1 (Form 1040) line 15, Part II — “Deductible part of self-employment tax”; it is an income deduction and does not reduce the SE tax itself

DOC
Schedule SE (2026 draft); Schedule 1 (2026 draft)

YEAR
2026 — IRS draft as of 2026-10-06

LINE
Schedule SE line 13; Schedule 1 lines 15, 26

CHECKED
2026-10-06

Update log

Changes are dated and kept. Old figures are never silently overwritten.

2026-10-11:

Tool published. The arithmetic replicates Article 2’s verified reading of Schedule SE (form text 2025, cross-checked on the 2026 draft posted May 21, 2026; claims checked 2026-10-06), including the $184,500 ceiling preprinted at line 7 of the 2026 draft. Acceptance: Article 2’s worked example — $80,000 of net profit, no W-2 wages — returns line 12 of $11,303.64 and line 13 of $5,651.82. Optional methods and church-employee income are not figured. The lines are re-verified against the final 2026 Schedule SE when it posts.