Quarterly Estimated Tax Calculator
Estimate quarterly estimated tax payments for self-employed and 1099 income from expected net income, an effective tax rate, self-employment tax, and tax already withheld.
How to use this tool
- Enter your expected annual net (1099) income.
- Set your effective income tax rate and self-employment tax rate.
- Subtract any tax already withheld or paid this year.
- Read total annual tax and the amount for each of the four quarters.
Plan your quarterly estimated taxes as a freelancer or contractor. Enter expected net income, your effective income and self-employment tax rates, and any tax already withheld to size each payment.
Formula
Income tax = Net income × Effective income tax rate
SE tax = Net income × Self-employment tax rate
Total annual tax = Income tax + SE tax
Each quarterly payment = max(0, Total annual tax − Already withheld) ÷ 4
How it works
People with self-employment or 1099 income generally have no employer withholding, so the tax authority expects estimated tax in four installments through the year. This calculator splits the year's expected liability into quarterly payments. It adds estimated income tax (your effective income tax rate applied to net income) and self-employment tax (Social Security and Medicare on net earnings), then subtracts any tax already withheld — for example from a separate W-2 job — before dividing by four.
The self-employment rate default of about 14.13% reflects the US combined 15.3% rate applied to 92.35% of net earnings, valid below the Social Security wage base; both this rate and the income tax rate are editable so the tool generalizes across years and situations. For precision, use your prior-year effective rates or a safe-harbor target. This estimate spreads the liability evenly and does not model uneven income, the annualized-income method, or underpayment penalties.
Reviewed by the AbraCalc Tax Desk. This calculator provides general information, not tax advice; confirm current rates and rules with your tax authority (for the United States, the IRS).
Worked example
$80,000 net 1099 income, 18% income tax, 14.13% SE, nothing withheld
- Income tax = 80,000 × 18% = 14,400.
- SE tax = 80,000 × 14.13% = 11,304.
- Total annual tax = 14,400 + 11,304 = 25,704.
- Nothing withheld, so amount owed = 25,704.
- Each quarterly payment = 25,704 ÷ 4 = 6,426.
Each quarterly payment = $6,426.00 (total annual tax $25,704.00)
Quarterly payment by net income (18% income tax, 14.13% SE, $0 withheld)
| Net income | Total annual tax | Each quarterly payment |
|---|---|---|
| $20,000 | $6,426.00 | $1,606.50 |
| $40,000 | $12,852.00 | $3,213.00 |
| $60,000 | $19,278.00 | $4,819.50 |
| $80,000 | $25,704.00 | $6,426.00 |
| $100,000 | $32,130.00 | $8,032.50 |
| $120,000 | $38,556.00 | $9,639.00 |
| $150,000 | $48,195.00 | $12,048.75 |
Key terms
- Estimated tax
- Periodic tax payments made on income that is not subject to withholding.
- 1099 income
- Income reported on a Form 1099 (contractor, freelance, gig), typically without withholding.
- Self-employment tax
- Social Security and Medicare tax paid by self-employed people on net earnings.
- Safe harbor
- Paying a set percentage of last year's tax to avoid an underpayment penalty.
Frequently asked questions
- When are quarterly estimated taxes due?
- In the US, estimated taxes are generally due in four installments (around April, June, September, and the following January). Check your authority's current calendar, as exact dates shift with weekends and holidays.
- What self-employment tax rate should I enter?
- Below the Social Security wage base, the US combined SE tax is about 14.13% of net income (15.3% applied to 92.35% of earnings). Above the wage base only the Medicare portion continues, so the effective rate falls.
- How do I avoid an underpayment penalty?
- Many jurisdictions offer a safe harbor — paying a set percentage of last year's tax (often 100% or 110%) — that avoids penalties even if you owe more. Use that target if your income is hard to predict.