Quarterly Estimated Tax Calculator

Estimate how much to pay in quarterly estimated federal income tax. Enter your expected annual tax and any withholding already paid (e.g. from a W-2 job). We divide the remaining amount into four equal payments. For planning only.

Quarterly estimated tax

How it works

Remaining tax = expected annual tax − withholding already paid (use $0 if none). Quarterly payment = remaining ÷ 4. We do not prorate by quarter; use for a simple equal-split estimate. IRS due dates are typically April 15, June 15, Sept 15, Jan 15.

When to use it

Use it when you have self-employment or other income not subject to withholding, or when you need to top up after a W-2 job. Pair with the self-employment tax calculator and the annual tax calculator for a full picture.

Frequently asked questions

Are the quarters equal?

Yes. We split the remaining tax into four equal payments. IRS may allow unequal amounts; check IRS guidelines.

What about state estimated tax?

This is federal only. Many states have their own estimated tax rules and due dates.

What if I over-withheld?

If withholding already paid is greater than expected tax, remaining is zero and no estimated payments are needed.