Roughly how much should a self-employed earner set aside each quarter for their federal estimated-tax payment, given expected self-employment income, any W-2 wages, and their expected federal marginal tax rate?
This tool is for: Self-employed individuals, freelancers, and 1099 contractors planning their federal quarterly estimated-tax payments · Hybrid earners with both 1099 self-employment income and a W-2 day-job who need a directional planning figure · Anyone budgeting cash flow around the IRS quarterly deadlines
- An educational planning estimate of one federal quarterly payment, equal to one-quarter of the projected annual federal liability
- The breakdown between the federal income-tax component and the self-employment-tax component
- A clear list of what this calculator does NOT compute — state/local tax, credits, deductions, safe-harbor compliance, penalties, withholding tables
Formulas Used
Self-Employment Tax (Federal)
SE Tax = (Net SE Earnings × 0.9235) × 0.153
Where: Net SE Earnings = Annual net self-employment income (gross minus deductible business expenses) (USD), 0.9235 = Statutory adjustment factor — only 92.35% of SE earnings are subject to SE tax (factor), 0.153 = Combined SE-tax rate: 12.4% Social Security + 2.9% Medicare (rate)
Source: IRS Topic No. 554 — Self-Employment Tax
Single-Rate Federal Income-Tax Component (Educational Approximation)
Income Tax Component = (Net SE Earnings − SE Tax / 2 + W-2 Wages) × Marginal Rate
Where: SE Tax / 2 = The deductible half of self-employment tax; reduces taxable earned income (USD), W-2 Wages = Annual W-2 wages or other earned income taxed at the same marginal rate (USD), Marginal Rate = User-entered federal marginal tax rate (percent)
Source: IRS Form 1040-ES — Estimated Tax for Individuals (worksheet methodology)
Quarterly Payment
Quarterly Payment = (Income Tax Component + SE Tax) / 4
Where: Income Tax Component = Federal income-tax estimate at the user's marginal rate (USD), SE Tax = Annual self-employment tax (USD)
Source: IRS — Estimated Taxes (consumer overview)
Key Insight
Self-employment tax is the leg most filers under-estimate when planning quarterly payments. At a 22% federal marginal rate, the SE-tax component on $60,000 of net SE income is roughly $8,500 — a figure that often surprises first-year freelancers who anticipated only the income-tax piece. Treating this calculator as a directional planner and cross-checking against IRS Form 1040-ES is the safe pattern.
Frequently Asked Questions
What does this calculator deliberately NOT compute?
Several things — by design. It does not check IRS safe-harbor compliance (the rules that determine whether you owe estimated taxes at all and whether your payments are large enough to avoid penalties). It does not project under-payment penalties or interest. It does not compute state, local, or city income tax. It does not apply tax credits (Child Tax Credit, EITC, premium tax credit, etc.) or deductions beyond the standard half-SE-tax deduction. It does not consult IRS Publication 15-T withholding tables. It does not subtract any W-2 withholding from the result. It is an educational planning estimate of one federal quarterly payment, nothing more.
Why does the calculator ask for my marginal tax rate instead of computing it from my income?
Federal income-tax brackets are tax-year-specific and change every year. To stay stable across tax years and avoid silently shipping outdated brackets, this V1 deliberately offloads the marginal-rate decision to the user. Look up the current IRS bracket table for your filing status, identify the rate that applies to your top dollar of income, and enter it here. If your income spans multiple brackets, this single-rate approximation overstates liability slightly for low-income earners and understates it slightly for high-income earners with substantial income above the bracket they entered.
Why doesn't the SE-tax figure cap at the Social Security wage base?
It would, in real life. The 12.4% Social Security portion of self-employment tax stops applying once your combined wages and SE earnings exceed the annual SSA wage base — that figure is the 'cap'. This V1 does not implement the cap because the wage base changes every year and we did not want to embed a tax-year-specific number that would silently go stale. The consequence is that for self-employment earnings above the wage base, the SE tax shown here is higher than what you would actually owe. We chose this conservative direction deliberately: a planning tool that overstates is safer than one that understates. If your SE earnings exceed roughly the prior-year wage base, treat the SE-tax figure as an upper bound and consult Form 1040-ES.
About This Calculator
Sources:
- IRS — Estimated Taxes (Small Businesses / Self-Employed overview) — Federal consumer overview of who must pay estimated taxes, how the four quarterly periods work, and the role of the Form 1040-ES worksheet
- IRS Form 1040-ES — Estimated Tax for Individuals — Authoritative worksheet methodology for computing annual estimated tax and dividing it into quarterly payments — the reference this calculator approximates educationally
- IRS Topic No. 554 — Self-Employment Tax — Federal definition of the self-employment-tax base (92.35% adjustment factor) and the combined 15.3% rate used in this calculator
- Social Security Administration — Contribution and Benefit Base (annual) — Authoritative annual Social Security wage base figure — referenced here as the boundary at which the 12.4% Social Security portion of SE tax would cap if this V1 implemented the cap (it does not)
Limitations:
- Federal scope only — no state, local, or city income tax; no state SDI, paid-family-leave, or other state payroll levies
- Self-employment tax is computed un-capped: the 12.4% Social Security portion is NOT capped at the annual SSA wage base, so for self-employment earnings above the wage base this output overstates SE tax (intentionally conservative for a planning tool)
- Federal income-tax component is a single-rate approximation using the user-entered marginal rate, not a full bracket-by-bracket computation
- Does not subtract any W-2 withholding the user may already have — the user must apply that offset manually
- Does not check IRS safe-harbor thresholds (110% prior-year, 100% prior-year, 90% current-year) and does not determine whether the user owes estimated taxes at all
- Does not project under-payment penalties or interest
- Does not apply credits (Child Tax Credit, EITC, premium tax credit, retirement-savings credit, etc.) or deductions beyond the standard half-SE-tax deduction
- Does not handle Additional Medicare Tax (0.9% surtax above the high-earner threshold) or Net Investment Income Tax
- Splits the annual estimate equally across four quarters — does not adjust for seasonal income or the IRS's unequal calendar-quarter periods
- Equal-quarterly outputs are rounded to two decimal places and may differ from the IRS worksheet by a few dollars due to rounding
When to consult a professional: Before paying any quarterly estimated tax derived from this output, especially in your first year of self-employment, after a major life change (marriage, divorce, child, sale of a business or property), if your income varies substantially across quarters, or if you are uncertain about safe-harbor compliance. A licensed tax professional or the IRS Form 1040-ES worksheet are the authoritative references
This calculator produces a directional, federal-only educational estimate of one quarterly estimated-tax payment for self-employed and hybrid earners. It is not a tax-filing tool, not a tax-advice service, and not a substitute for the IRS Form 1040-ES worksheet or a licensed tax professional. It does not check IRS safe-harbor compliance, does not project under-payment penalties or interest, does not compute state, local, or city income tax, does not apply credits or deductions beyond the standard half-SE-tax deduction, and does not consult IRS Publication 15-T withholding tables. Self-employment tax components are tied to the long-standing 12.4% / 2.9% federal identity; any annually-changing thresholds (such as the Social Security wage base) are not modelled in this V1.