South Carolina Quarterly Tax Estimate Calculator — 2026

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

Quick South Carolina Tax Estimate

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

State Tax on $80K Profit
$1,235.13
SE Tax
$11,303.64
Effective Rate
21.7%
Marginal Rate
12%
Full South Carolina Tax Calculator →

South Carolina Tax Information

State Income TaxYes
Top Marginal Rate5%
Sales Tax0%
LLC Filing Fee$0
Annual Report Fee$None
Standard DeductionN/A

Self-employed pay both federal and South Carolina state tax.

South Carolina Income Tax Brackets (2026)

Tax RateFromTo
2%$0$30,000
5.2%$30,000No limit

South Carolina Quarterly Tax Deadlines

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

Frequently Asked Questions

When are quarterly taxes due in South Carolina?
Federal quarterly deadlines: April 15 (Q1), June 15 (Q2), September 15 (Q3), January 15 (Q4). South Carolina follows the same schedule for state estimated payments.
How do I calculate quarterly taxes in South Carolina?
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 South Carolina?
The IRS charges interest on underpayments (currently 8% annual rate). South Carolina may impose additional penalties. Even partial payments reduce your penalty.
Can I skip quarterly payments in South Carolina?
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 South Carolina?
Pay federal taxes via IRS Direct Pay (free), EFTPS, or credit card (fees apply). Pay South Carolina taxes through the state Department of Revenue website.