Illustrate a simplified US self-employment tax cash reserve

Separate a simplified reserve from an actual estimated-tax payment

Under the regular US method, net self-employment earnings generally use a 92.35% factor. The familiar 15.3% combines Social Security and Medicare components, but the Social Security component has an annual wage limit and coordinates with wages. This example assumes no wages or other self-employment income and earnings below that limit.

At 100,000 profit, the simplified tax is 14,129.55 and half is 7,064.775 before display rounding. Applying an assumed 22% income-tax rate after that half-tax deduction gives a rough combined cash reserve of 8,643.82 per quarter.

This is not a Schedule SE or 1040-ES calculator. It omits progressive brackets, filing status, credits, QBI, withholding, safe-harbor rules, uneven-income payment methods, Additional Medicare Tax, state-specific rules and special self-employment cases. Actual payment dates are not four equal calendar quarters. Verify the applicable tax-year forms before using figures for filing.

Annual Self-Employment Tax and Quarterly Estimated Tax Reserve formulas

Illustrates the regular-method net-earnings threshold of 400 before applying the below-cap rate. Special cases are outside this example. Negative business profit produces zero in this simplified SE component, not necessarily zero overall tax.

=ROUND(IF(MAX(0,A2)*0.9235<400,0,MAX(0,A2)*0.9235*0.153),2)

Rough equal-period cash reserve

Uses a chosen nonnegative rate as an illustration, not a tax-bracket calculation or required payment. The below-wage-cap and no-other-earnings assumptions are essential.

=LET(se,IF(MAX(0,A2)*0.9235<400,0,MAX(0,A2)*0.9235*0.153),ROUND((se+(MAX(0,A2)-se/2)*B2)/4,2))

Further reading

• Microsoft Support — MAX function
• IRS — Publication334, self-employment tax