Taxes · 2026 federal

Quarterly tax planner

Compare safe-harbor targets with your projected tax bill and payments made.

Example amounts. Replace with your numbers.

Federal payment targets

Projected 2026 federal tax

Use your full-year federal tax after applicable credits but before withholding and estimated payments (Form 1040-ES worksheet line 11c). Include SE tax and other federal taxes. Not profit or the amount owed with your return.

Expected full-year federal withholding

All wage, pension and other federal income tax withholding. Exclude Social Security/Medicare deductions and estimated payments.

My 2025 return covers a full 12-month year and is eligible for the prior-year safe harbor

2025 tax for safe-harbor purposes

Prior-year tax as defined in the Form 1040-ES / 2210 instructions; not your refund or balance due. Certain adjustments may be needed.

2025 adjusted gross income

Your prior-year AGI, not gross business revenue.

2026 filing status is married filing separately

Estimated payments already made

Enter each payment in the period when it was actually made. Do not move a late payment into an earlier period. Include a prior-year overpayment applied to Q1 in Q1.

Paid in Q1 payment period

Due April 15, 2026. Period begins after the preceding installment deadline.

Paid in Q2 payment period

Due June 15, 2026. Period begins after the preceding installment deadline.

Paid in Q3 payment period

Due September 15, 2026. Period begins after the preceding installment deadline.

Paid in Q4 payment period

Due January 15, 2027. Period begins after the preceding installment deadline.

Annual estimated-payment target

$15,000

Lower modeled safe-harbor target, less full-year withholding. Timing still matters.

Remaining to annual target: $15,000
Projected balance if no more paid: $20,000

90% of projected 2026 tax: $22,500
Prior-year target: $20,000 (100%)
Federal withholding: $5,000
Estimates entered as paid: $0

Safe harbor is about underpayment-penalty exposure, not eliminating the final bill. Paying a missed installment later does not erase a prior underpayment.

Equal-installment schedule

Assumes income earned evenly and withholding allocated evenly. “Gap” is cumulative through each deadline; do not add the four gaps together.

Deadline	Installment target	Paid through date	Gap to cumulative target
April 15, 2026	$3,750.00	$0.00	$3,750.00
June 15, 2026	$3,750.00	$0.00	$7,500.00
September 15, 2026	$3,750.00	$0.00	$11,250.00
January 15, 2027	$3,750.00	$0.00	$15,000.00

How this estimate works

2026 calendar-year federal individual planning, using your supplied tax projections. The general target is the smaller of 90% of current-year tax or 100% of prior-year tax, increased to 110% if prior-year AGI exceeds $150,000 ($75,000 for married filing separately). Prior-year eligibility and Form 2210 adjustments must be confirmed.

No penalty calculation is performed. Annualized income, actual withholding timing, disaster relief, farming/fishing, nonresident rules, state payments and special exceptions are outside this model. An annual excess does not necessarily cure earlier installment shortages. A full-year prior return with zero liability may eliminate estimates, but current-year tax can still be due.

IRS 2026 Form 1040-ES and due dates · IRS underpayment guidance

Federal payment targets

Equal-installment schedule

Put your numbers into a plan.