Tax Deadline Calculators
Quick calculators for extensions and quarterly estimated taxes.
Extension Deadline Calculator
Estimate your extension deadline based on the original due date.
Estimated extension deadline
October 15, 2026
Quarterly Estimate Builder
Plan quarterly payments for 2026 based on entity type.
Apr 15, 2026
Quarterly estimate due
Jun 15, 2026
Quarterly estimate due
Sep 15, 2026
Quarterly estimate due
Jan 15, 2027
Quarterly estimate due
IRS estimate schedule sourced from federal deadlines list.
Federal baseline
Use these dates as a baseline when estimating state due dates.
Form 1040 Schedule C
Due Apr 15, 2026
Form 1065
Due Mar 16, 2026
Form 1120-S
Due Mar 16, 2026
Form 1120
Due Apr 15, 2026
Depends on classification
Due Apr 15, 2026
Form 990 / 990-EZ / 990-PF
Due May 15, 2026