Tax calculator

Free estimated quarterly tax calculator

Enter your expected income, deductions, and prior-year tax — this quarterly estimated tax calculator shows each 2024 payment amount and confirms your safe-harbor threshold, updated live, as you type.

InputsLive
Gross pay (this period)
$
Federal income tax rate
%
Estimate from your tax bracket or W-4.
State income tax rate
%
Enter 0 if your state has no income tax.
Other deductions
$
Health insurance, 401(k), etc.
Result
Net pay
$3,267.5
Deductions: $1,732.5 · FICA: $382.5
Net pay$3,267.5
Federal tax$1,100
State tax$250
FICA (SS + Med)$382.5

Estimated only. Actual withholding depends on your W-4 elections, filing status, and local laws. Consult your payroll provider for exact figures.

Results are estimates. Consult a professional.

How it's calculated

How the estimated quarterly tax calculator works

The US tax system is pay-as-you-go: income tax is due when income is earned, not just when you file in April. For employees, employers do this automatically through payroll withholding. For the self-employed, freelancers, investors with dividends or capital gains, and anyone whose withholding is insufficient, the IRS requires quarterly estimated tax payments. The calculator figures out how much to send and when.

Total estimated tax = expected income tax + self-employment (SE) tax credits withholding
SE tax = net SE income × 92.35% × 15.3% (up to SS wage base, then 2.9% above)
Quarterly payment = total estimated tax ÷ 4
Safe harbor option A: pay 100% of prior-year tax (110% if prior AGI > $150,000)
Safe harbor option B: pay 90% of current-year tax
IRS Publication 505: Tax Withholding and Estimated Tax; Form 1040-ES (2024).
Example

Worked example: freelance consultant with no withholding

Example: Single freelancer, $95,000 net SE income, no W-2

Taylor is a single freelance consultant with $95,000 in expected net self-employment income for 2024 and no W-2 withholding. Taylor's prior-year tax was $28,000 and prior AGI was $112,000 (below $150,000, so the 100% safe harbor applies). Here is exactly how Taylor's quarterly payments are calculated.

Step 1 — SE tax: $95,000 × 92.35% = $87,733 × 15.3% = $13,423
Step 2 — Deduct ½ SE tax from income: $95,000 $6,712 = $88,288
Step 3 — Standard deduction (single, 2024): $88,288 $14,600 = $73,688 taxable income
Step 4 — Income tax on $73,688: ~$11,718
Step 5 — Total estimated tax: $11,718 + $13,423 = $25,141
Step 6 — Quarterly payment: $25,141 ÷ 4 = $6,285
Safe harbor check: prior-year tax $28,000 ÷ 4 = $7,000/quarter (higher — use current-year method)
$6,285 per quarter
Taylor sends four payments of $6,285 — due April 15, June 17, September 16, and January 15, 2025 — covering the full estimated tax liability and avoiding the underpayment penalty.
Quick reference

2024 quarterly due dates and safe-harbor payments

The table below shows the four 2024 payment deadlines and illustrative quarterly payment amounts based on total expected tax, using the current-year method (÷ 4). Safe-harbor amounts shown assume prior AGI ≤ $150,000; if your prior AGI exceeded $150,000 multiply the prior-year tax by 110% before dividing by 4.

Due datePeriod covered$50k expected tax$75k expected tax$100k expected tax$150k expected tax
April 15, 2024Jan 1 – Mar 31$12,500$18,750$25,000$37,500
June 17, 2024Apr 1 – May 31$12,500$18,750$25,000$37,500
September 16, 2024Jun 1 – Aug 31$12,500$18,750$25,000$37,500
January 15, 2025Sep 1 – Dec 31$12,500$18,750$25,000$37,500

Source: IRS Form 1040-ES (2024) payment vouchers. Amounts shown are equal-quarter estimates using the current-year method. Annualized income installment method (Schedule AI) may allow unequal payments for uneven income.

Practical tips

Tips for estimated quarterly tax payments

Getting quarterly payments right requires a little planning at the start of the year and a mid-year check-in. These five practices keep freelancers and investors out of penalty territory.

  • Default to the prior-year safe harbor if your income is unpredictable. Paying 100% of last year's tax (or 110% if prior AGI exceeded $150,000) in four equal installments fully protects you from the underpayment penalty — even if you end up owing much more at filing. It removes guesswork when income swings are hard to forecast.
  • Use the annualized income installment method for lumpy income. If you earn most of your income in Q3 (say, from a large project or capital gain), Schedule AI lets you pay more later and less earlier without incurring a penalty for the underpaid early quarters.
  • Set aside 25–30% of every invoice or freelance payment into a separate savings account. Transfer it immediately so it is never mentally available to spend. This creates a self-funded quarterly tax reserve that keeps cash flow predictable.
  • Adjust payments immediately after a major income change. A large unexpected client, a big capital gain, or a real-estate sale can push you into a higher bracket mid-year. Recalculate your total estimated tax and increase Q3 or Q4 payments to catch up.
  • Pay online via IRS Direct Pay or EFTPS — never mail a paper check without tracking. Electronic payments post instantly and generate a confirmation number. Missing a deadline by even one day starts penalty interest; online payment eliminates USPS delivery risk.
Accuracy & limits

Accuracy and limitations

This calculator estimates quarterly payments using the equal-installment method (total ÷ 4) and applies the 2024 self-employment tax rate of 15.3% on net earnings up to $168,600 (Social Security wage base), then 2.9% (Medicare only) above that. It uses 2024 standard deductions and income tax brackets. It does not calculate state estimated taxes — most states that have income tax require separate quarterly payments on their own schedule.

The calculator does not model the annualized income installment method (Form 2210, Schedule AI), which can reduce required payments in early quarters if income is back-loaded. If your income varies widely by quarter, consult IRS Form 2210 instructions or a tax professional. The underpayment penalty rate changes each quarter; the calculator uses the current IRS rate (federal short-term rate + 3%) as a planning estimate.

Glossary

Estimated tax terms defined

Periodic prepayments of federal (and state) income tax and self-employment tax due when income is not subject to payroll withholding, or when withholding is insufficient to cover the year's expected liability.
The Social Security and Medicare contributions paid by self-employed individuals — 12.4% Social Security (up to $168,600 in 2024) plus 2.9% Medicare on 92.35% of net self-employment income. Half is deductible as an above-the-line adjustment.
A threshold that, if met, eliminates the underpayment penalty regardless of the final tax owed: either 90% of the current year's tax, or 100% of the prior year's tax (110% if prior AGI > $150,000).
An interest-based penalty charged when you owe more than $1,000 at filing and did not pay enough through withholding and estimated payments. The rate is the IRS short-term federal rate plus 3 percentage points, compounded daily.
IRS form and payment voucher used to calculate and submit estimated quarterly tax payments. Four vouchers are included, one per due date.
Electronic Federal Tax Payment System — a free IRS service (irs.gov/payments) for paying estimated taxes online or by phone. Enrollment takes a few days; plan ahead for your first payment.
An IRS calculation (Form 2210, Schedule AI) that bases each quarter's required payment on the income actually earned through that quarter. Reduces required early-quarter payments for taxpayers whose income is earned unevenly across the year.
About

About this estimated quarterly tax calculator

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Questions

Frequently asked questions about the free estimated quarterly tax calculator

An estimated quarterly tax calculator is a free online tool that helps you calculate quarterly estimated tax payments. Self-employed and high earners pay quarterly estimates. It runs entirely in your browser with instant results and no sign-up.
No — these are simplified estimates based on 2024 brackets. Real tax filing requires considering all your deductions, credits, AMT, state taxes, and the latest IRS guidance. Use professional tax software or a CPA for filing.
Marginal rate is what you pay on your next dollar of income. Effective rate is total tax ÷ total income — typically much lower because of the progressive brackets and deductions.
Federal only. State tax varies by jurisdiction; some states have no income tax (TX, FL, WA, etc.), others up to 13%+ (CA, NY). Add state tax separately based on your state.

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