Idaho Quarterly Tax Estimate Calculator — 2026

Estimate your quarterly tax payments to avoid IRS underpayment penalties. Get your personalized 1040-ES payment schedule.

Quick Idaho Tax Estimate

Based on Idaho's tax rates for 2026. Enter your details for a personalized calculation.

State Tax on $80K Profit
$0
SE Tax
$11,303.64
Effective Rate
20.2%
Marginal Rate
12%
Full Idaho Tax Calculator →

Idaho Tax Information

State Income TaxYes
Sales Tax0%
LLC Filing Fee$0
Annual Report Fee$None
Standard DeductionN/A

Self-employed pay both federal and Idaho state tax.

Idaho Quarterly Tax Deadlines

Q1
Apr 15
Q2
Jun 16
Q3
Sep 15
Q4
Jan 15

Frequently Asked Questions

When are quarterly taxes due in Idaho?
Federal quarterly deadlines: April 15 (Q1), June 15 (Q2), September 15 (Q3), January 15 (Q4). Idaho follows the same schedule for state estimated payments.
How do I calculate quarterly taxes in Idaho?
Estimate your annual income, subtract deductions, calculate tax, and divide by 4. Or use the safe harbor method: pay 100% of last year's tax (110% if AGI > $150K). Our calculator above does this automatically.
What happens if I miss a quarterly payment in Idaho?
The IRS charges interest on underpayments (currently 8% annual rate). Idaho may impose additional penalties. Even partial payments reduce your penalty.
Can I skip quarterly payments in Idaho?
You can skip if you expect to owe less than $1,000 total, had zero tax liability last year, or your withholding covers 90%+ of this year's tax. Otherwise, skipping triggers penalties.
How do I pay quarterly taxes online in Idaho?
Pay federal taxes via IRS Direct Pay (free), EFTPS, or credit card (fees apply). Pay Idaho taxes through the state Department of Revenue website.