Advanced Corporate Tax Calculator 2026

Compute federal, state, CAMT, and BEAT liabilities for C-Corps, S-Corps, and multinational enterprises. Updated for the 2026 tax code, including the Corporate Alternative Minimum Tax (CAMT)[citation:10].

Real-Time Calculation Engine: This tool provides instant, professional-grade estimates for strategic planning, budgeting, and compliance. It models complex provisions like the 15% CAMT on financial statement income and the 10% BEAT for multinationals[citation:4][citation:10].

Input Your Financial Data

S-Corps pass income to shareholders; calculate shareholder-level taxes separately.
Net income after all allowable deductions (COGS, wages, interest, depreciation)[citation:4].
Combined state + local rate. Multistate operations require apportionment[citation:10].
Average Annual AFSI (3-year). >$1B triggers CAMT[citation:10].
Deductible payments to foreign affiliates. >3% of deductions may trigger BEAT[citation:10].
Used for BEAT threshold calculation (Base Erosion % = Payments / Total Deductions).

Calculated Tax Liability Live Results

$0.00
Federal Corporate Income Tax (21%) $0.00
State & Local Corporate Tax $0.00
Corporate AMT (CAMT) Exposure $0.00
Base Erosion & Anti-abuse Tax (BEAT) $0.00
Estimated Total Corporate Tax Liability $0.00
Effective Tax Rate 0.0%

Core Tax Formula

Total Tax = (Taxable Income × 21%) + (Taxable Income × State Rate) + max(0, CAMT - Regular Tax) + BEAT[citation:4][citation:10]

Where:

  • CAMT = 15% × Adjusted Financial Statement Income (AFSI), if AFSI > $1B avg.[citation:10]
  • BEAT = 10% × (Modified Taxable Income – Regular Tax), if base erosion % > 3%[citation:10].
  • Modified Taxable Income ≈ Taxable Income + Base Erosion Deductions.
Disclaimer: This tool provides estimates for strategic planning. Actual tax liability depends on specific facts, credits, NOLs, and transactions. Consult a qualified tax professional for compliance and filing.

Practical Use Cases & Real Examples

1. Tech Startup (C-Corp, Pre-CAMT)

Scenario: A growing tech C-Corp in California with $5M taxable income and $800M AFSI.

Calculation: Federal Tax: $5M × 21% = $1.05M. CA State Tax: $5M × 8.84% = $442k. CAMT: Not applicable (AFSI < $1B).

Total: $1,492,000 (Effective Rate: ~29.8%).

2. Large Multinational Manufacturer

Scenario: C-Corp with $50M US income, $1.5B AFSI, and $4M in base erosion payments on $30M deductions.

Calculation: Federal: $10.5M. State (6% avg): $3M. CAMT: ($1.5B × 15%) - Regular Tax = $225M - $13.5M = $211.5M (applies!). BEAT: Base erosion % = 13.3% (>3%), so 10% × ($50M + $4M - $13.5M) = $4.05M.

Total: $228.05M (CAMT dominates).

3. Professional Services S-Corporation

Scenario: An architecture firm elected as S-Corp with $2M net income in Texas.

Calculation: $0 Federal Corporate Tax[citation:10]. Texas Margin Tax (~1% on apportioned margin): ~$20k. Income flows to shareholders' personal returns (subject to individual rates + 3.8% Net Investment Income Tax).

Frequently Asked Questions (FAQ)

What is the 2026 federal corporate income tax rate in the US?
The US federal corporate income tax rate for C-Corporations is a flat 21% on taxable profits. This rate was established by the Tax Cuts and Jobs Act of 2017[citation:4][citation:10].
How do I calculate my company's total corporate tax liability?
Total Corporate Tax Liability = (Taxable Income × 21%) + State Tax Liability + Applicable CAMT + Applicable BEAT. You must calculate each component, starting with federal taxable income, then add state taxes (which vary by location), and finally apply any additional minimum taxes like the Corporate Alternative Minimum Tax (CAMT) or Base Erosion and Anti-abuse Tax (BEAT) if your company meets the thresholds[citation:4][citation:10].
What is the Corporate Alternative Minimum Tax (CAMT) and who pays it?
The CAMT is a 15% minimum tax on the Adjusted Financial Statement Income (AFSI) of large corporations. It applies to C-corporations with an average annual AFSI exceeding $1 billion over three years. For multinational groups, a second test requires US operations' AFSI to exceed $100 million[citation:10]. It ensures large profitable companies pay a minimum level of tax.
Are S-Corporations subject to corporate income tax?
No, S-Corporations are generally not subject to federal corporate income tax at the entity level[citation:10]. Instead, profits and losses 'pass through' to the shareholders' individual tax returns. However, some states may impose a minimal franchise or excise tax on S-Corps.
What is the Base Erosion and Anti-abuse Tax (BEAT)?
The BEAT is an additional tax designed to prevent multinational corporations from shifting profits out of the US via deductible payments to foreign related parties. It is generally 10% of 'modified taxable income' for applicable corporations (those with gross receipts over $500M and base erosion payments exceeding 3% of total deductions)[citation:10].
How do state taxes affect my total corporate tax burden?
State corporate income taxes significantly increase the total tax burden. Rates vary from 0% to over 10%, and the taxable base is typically federal taxable income with state-specific modifications[citation:10]. A company operating in multiple states must apportion its income, which can lead to complex calculations.
Can this calculator be used for international tax planning?
While this calculator provides a strong foundation for US federal, state, and minimum taxes, comprehensive international planning requires consideration of foreign tax credits, GILTI, FDII, and treaty provisions. For complex multinational operations, consult a tax professional and use specialized tax provision software[citation:7].