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Quarterly Estimated Tax Calculator

U.S. only tools

The US tax system is pay-as-you-go: most people prepay through withholding, but self-employment income, interest, dividends and pensions have no paycheck to withhold from. For that portion the IRS expects four estimated payments a year - and four equal installments are the simplest way to satisfy it.

Quarterly Estimated Tax Calculator - Danfio

https://danfio.com/tools/quarterly-estimated-tax-calculator/ - printed from this page

Currency: USD ($) - display only, nothing was converted

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Wages from an employer job, which already carry withholding.

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Box 2 income tax withheld from that job - not the FICA share.

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Freelance, 1099 or business profit with no withholding at all.

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Interest, dividends, pension or rental income that never withholds.

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SEP-IRA, SIMPLE or Solo 401(k) contributions made for yourself.

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Your 2025 Form 1040 line 24 amount. Leave at zero to use only this year’s 90% safe harbor.

Results update as you type. Nothing leaves your device.

Currency symbol

Symbol only - nothing is converted and no exchange rate is used. Figures quoted in the explanation text stay as the sources publish them.

Estimated tax still to pay

$7,776.48

Suggested quarterly payment
$1,944.12
Total federal tax
$10,640.53
Withheld so far
$1,800.00

Your federal bill, built up

LineAmount
W-2 wages$30,000.00
Self-employment profit$40,000.00
Net earnings subject to self-employment tax$36,940.00
Self-employment tax$5,651.82
Federal income tax$4,988.71
Total federal tax$10,640.53
Less federal income tax withheld-$1,800.00
Still to pay if nothing else is held back$8,840.53

The W-2 job already paid its share of FICA from the paycheck, so only the income tax withheld counts here. The self-employment half is on top and is almost never covered.

Four equal payments (safe-harbor plan)

PaymentRoughly dueAmount
Payment 1April 15$1,944.12
Payment 2June 15$1,944.12
Payment 3September 15$1,944.12
Payment 4January 15 next year$1,944.12
Total safe-harbor amount$7,776.48

The penalty-safe floor is the smaller of 90% of this year’s tax or 100% (110% for higher-income filers) of last year’s, minus withholding. Four equal amounts is the simplest schedule; income that arrives unevenly can use the annualised method instead.

Paying $7,776.48 in four installments of $1,944.12 keeps you above the 90% floor for this year. Add last year’s tax (line 24 of your 2025 return) to unlock the 100%/110% safe harbor, which can be lower.

Enter your wages, your self-employment profit and what your paychecks already withheld, and this calculator builds the full federal bill, subtracts the withholding, and shows the safe-harbor amount - the smallest total that keeps you out of the underpayment penalty - split into the four payments.

About this quarterly estimated tax calculator

So that the tax does not land in one spring bill, it is paid across the year in quarters, and the plan behind those numbers is the work here. It exists because the quarterly payment system is the part of US tax that surprises freelancers most: no paycheck, no withholding, and a bill that quietly arrives in April. It builds the federal bill from the same 2026 calculation the rest of the site uses, subtracts the withholding, and prices the four-installment safe-harbor plan.

It is deliberately the regular method: the annualised-income worksheet, farming and fishing rules and state estimates sit outside it, and everything runs in your browser with no upload and no account. The figures come from the official IRS pages named on the page, and the page is reviewed on a schedule and corrected openly when the annual numbers change. An estimate, not a return, and not tax advice.

How this quarterly estimated tax calculator works

Why four payments at all

No employer is withholding tax on freelance profit, so there is nothing to stop the whole bill from arriving on April 15. The law closes that gap with Form 1040-ES: four estimated payments covering the tax your withholding does not.

The due dates are fixed - April 15, June 15, September 15 and January 15 of the following year. Four equal amounts that add up to the required total is the regular-installment method, and it is the plan this page prices. Paying the same figure four times is simple enough to keep, which is most of its value.

The schedule only appears when something is still owed after withholding. When the paycheck already covers the federal bill, the page says so instead of printing four empty rows, because a table of zeros reads like a plan when there is nothing to plan.

The bill has two halves

Self-employment profit pays a 15.3% tax of its own - Social Security and Medicare on 92.35% of net earnings - on top of ordinary income tax. Retirement contributions entered on the page reduce the profit the self-employment tax is built on, and are capped at the profit itself.

Interest, dividends, pension and rental income behave differently: they add income tax at the marginal rate and no self-employment tax, which is why the page prices them as a separate line rather than folding them into the profit figure.

Only income tax already withheld from a W-2 job counts against the bill. The FICA taken from that paycheck was paying that job’s payroll tax, not this one, so counting it again would understate what still has to be paid. W-2 wages still share the Social Security wage base with the self-employment profit, which is how the two incomes interact.

The safe harbor that removes the penalty risk

An underpayment penalty applies when withholding plus estimates are too low. Publication 505 sets the floor at the smaller of two anchors: 90% of the tax on this year’s return, or 100% of last year’s tax - 110% when last year’s adjusted gross income was above $150,000, or $75,000 for married filing separately.

Both anchors are measured after subtracting what was already withheld, and the page takes the smaller of the two as the amount still owed. Last year’s total is the predictable anchor because it is known when the year starts, which is why many planners choose it even when this year’s 90% line would be lower.

Divide that required amount by four and you have the quarterly figure. It is the smallest schedule that stays above the floor - paying more is allowed, but it is a prepayment, not a requirement.

Uneven income and the annualised method

The four-equal-installments plan assumes income arrives evenly. A business that earns almost nothing until December would overpay the first three quarters only to owe a large fourth, which is why Publication 505 offers an annualised income installment method.

Farming and fishing income carry their own special rules. This page prices the regular method only: if income is sharply seasonal, the next step is the annualised worksheet in Publication 505, Worksheet 2-9, rather than a different setting here.

The page also does not calculate the penalty itself or the interest that accrues on a late payment; those depend on when each installment was short and for how long, and Form 2210 is where the IRS works that out. What this page gives you is the floor that keeps the question from arising.

Worked examples

Each example below was run through the calculator on this page when the site was built, so the numbers match what you see when you enter the same inputs.

A W-2 job plus $40,000 of freelance profit

W-2 wages for the year: $30,000.00 · Federal income tax withheld: $1,800.00 · Self-employment profit: $40,000.00

Estimated tax still to pay

$7,776.48

Suggested quarterly payment: $1,944.12 · Total federal tax: $10,640.53 · Withheld so far: $1,800.00

The profit pays self-employment tax plus income tax; the $1,800 withheld only touches the wage side, so most of the bill remains.

Using last year’s tax as the anchor

W-2 wages for the year: $30,000.00 · Federal income tax withheld: $1,800.00 · Self-employment profit: $40,000.00 · Last year’s total tax: $8,500.00

Estimated tax still to pay

$6,700.00

Suggested quarterly payment: $1,675.00 · Total federal tax: $10,640.53 · Withheld so far: $1,800.00

Adding the prior-year total turns on the 100% safe harbor, which can produce a smaller required amount than this year’s 90% floor.

Fully self-employed, no W-2 at all

W-2 wages for the year: $0.00 · Federal income tax withheld: $0.00 · Self-employment profit: $90,000.00 · Other income with no withholding: $4,000.00

Estimated tax still to pay

$18,176.35

Suggested quarterly payment: $4,544.09 · Total federal tax: $20,195.94 · Withheld so far: $0.00

With no withholding anywhere, the quarterly payments carry the entire self-employment and income tax bill.

Withholding already covers the bill

W-2 wages for the year: $140,000.00 · Federal income tax withheld: $32,000.00 · Self-employment profit: $0.00 · Other income with no withholding: $0.00

Estimated tax still to pay

$0.00

Suggested quarterly payment: $0.00 · Total federal tax: $22,334.00 · Withheld so far: $32,000.00

When withholding clears the 90% floor, nothing is due as estimates - the page says so instead of pricing a plan.

Frequently asked questions

Who has to make quarterly estimated payments?

Anyone whose withholding and credits fall below the safe-harbor floor - typically because they have self-employment, interest, dividends, pension or rental income with no withholding. Employees whose W-2 covers 90% of the bill usually do not need to.

What if I pay less than the safe harbor?

The difference can trigger an underpayment penalty, calculated on the amount and the time it was overdue, even if the return itself shows little or nothing owed. The 90%/100% floor is exactly the amount that avoids that penalty.

Can I pay the full amount in one payment instead of four?

You can, but the penalty looks at each quarter separately, so an early year-end lump usually overpays the later quarters and underpays the earlier ones. Four on-time installments is the simplest way to stay covered.

How do I actually pay the estimated tax?

Form 1040-ES vouchers are the paper path; Direct Pay, EFTPS and your IRS online account take the payments electronically. The due dates and safe-harbor amounts on this page are the planning numbers that sit behind whichever one you use.

Do I still owe a penalty if my withholding was 90% but I owe more?

No - 90% of this year’s tax (or the prior-year anchor) is the point at which the underpayment penalty stops applying, even if you still owe the rest at filing. You owe the tax; you do not owe the penalty.

Why is interest income taxed but not self-employment taxed here?

Interest, dividends and pension income are ordinary income with no FICA or self-employment tax attached, so they add income tax at the marginal rate only. Self-employment profit carries both the 15.3% tax and income tax, which is the distinction this page models.

Assumptions and sources

  • Estimated tax, the four due dates, the underpayment penalty and the safe-harbor 90% / 100% / 110% floor: IRS Publication 505 (2026), Tax Withholding and Estimated Tax, verified against the official source and kept on record.
  • Self-employment tax on 92.35% of profit at 15.3%, the one-half deduction and the $400 threshold: IRS Topic no. 554, verified against the official source and kept on record.
  • Ordinary income brackets and the standard deduction: IRS Revenue Procedure 2025-32 (the 2026 inflation adjustments).
  • This page prices the regular four-equal-installments method; the annualised method for uneven income and the special farming/fishing rules are outside it.

Last reviewed 2026-10-09. An estimate, not a return, and not tax advice. Read the full disclaimer.

Where a figure on this page comes from an official agency — HUD, IRS, FICO or a state body — the site keeps a dated snapshot of the source page in its sources library, and a scheduled job re-checks that snapshot, so the number can be traced back to the document it came from.

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