Idaho Quarterly Tax Calculator
Calculate your estimated quarterly tax payments for federal and Idaho state taxes. Designed for self-employed individuals, freelancers, and independent contractors.
ID State Tax: Flat 5.8%
Quarterly Payment Amount
$6,671
Per quarter (4 remaining)
Annual Tax Breakdown
2026 Payment Schedule
Jan 1 - Mar 31
Due: April 15, 2026
$6,671
Apr 1 - May 31
Due: June 15, 2026
$6,671
Jun 1 - Aug 31
Due: September 15, 2026
$6,671
Sep 1 - Dec 31
Due: January 15, 2027
$6,671
Don't miss your quarterly payments!
The IRS may charge penalties and interest if you underpay or pay late. Consider setting up automatic payments or calendar reminders.
Idaho Quarterly Tax Highlights
Idaho has a flat 5.8% income tax rate
Recently converted from progressive to flat tax
Use Form 51 for quarterly payments
Simple calculation with single rate
Idaho Quarterly Tax FAQ
What is Idaho's income tax rate?
Idaho has a flat 5.8% income tax rate. The state recently converted from a progressive tax system to a flat tax, simplifying calculations for all taxpayers.
Official References
This calculator uses current federal and Idaho tax rates and schedules:
- IRS Estimated Tax Guidelines
Federal quarterly tax requirements and Form 1040-ES
- Idaho State Tax Commission
Official Idaho tax authority
- IRS Self-Employment Tax
Social Security and Medicare tax information
This calculator provides estimates based on 2026 tax rates. Your actual tax liability may vary based on deductions, credits, and other factors. Consult a tax professional for personalized advice.