OpenChainGraph Suite · ART-339 · US Payroll Compliance

Gross-to-Net Payroll Calculator

FICA (Social Security 6.2% up to the wage base for the selected tax year, Medicare 1.45% uncapped, Additional Medicare Tax 0.9% on cumulative wages over $200,000), pretax deduction ordering, and net pay for a single pay period. Consumes ART-338 Federal Withholding Calculator's output as its federal_withholding_per_period input.

IRC 3101/3121 SSA 2025 Wage Base FICA Federal Only

🔒 All inputs are processed locally in your browser. No data is transmitted. Do not enter real personal data — use synthetic or anonymised inputs only.

⚠ Federal FICA and net pay only. Not tax advice. State/local withholding and state disability/unemployment employee contributions are out of scope for this tool.

Pay & YTD Tracking

Tax year

Selects the SSA contribution and benefit base. 2026: $184,500. 2025: $176,100.

Gross wages this pay period ($)

Federal withholding this period ($)

From ART-338 Federal Withholding Calculator, or your own figure.

YTD FICA wages before this period ($)

Cumulative FICA-taxable wages already paid this calendar year.

Deductions

Pretax 401(k) / HSA / Section 125 ($)

Reduces both FICA wages and federal-taxable wages.

Post-tax deductions ($)

Roth deferrals, garnishments, after-tax premiums. Reduces net pay only.

FICA Detail

Execution Hash (SHA-256)

Ask your agent

Copy this paragraph into Claude, OpenClaw, or any MCP-aware agent to run this exact tool, with this sample, and verify the artifact.

Run the AINumbers MCP tool `compute_gross_to_net`. Task: Gross-to-net payroll calculation: FICA (Social Security 6.2% up to the OASDI contribution and benefit base for the selected tax year, Medicare 1.45% uncapped, Additional Medicare Tax 0.9% on cumulative wages over $200,000 per IRC 3101(b)(2)), pretax deduction ordering (401(k)/HSA/Section 125 reduce both FICA and federal-taxable wages), and net pay.
Call it with arguments: {"policy_parameters":{"tax_year":"2026","gross_wages_per_period":5000,"federal_withholding_per_period":0,"pretax_reduces_fica_and_fit":0,"post_tax_other_deductions":0,"ytd_fica_wages_before_period":180000}}
Verify before trusting: call `verify_execution_hash` on mcp.ainumbers.co (https://mcp.ainumbers.co/mcp) with the parameter `claimed_hash` set to the returned `execution_hash`, passing the full artifact the run returned (the object containing `policy_parameters` + `output_payload` + `execution_hash`; equivalently `policy_parameters` + `output_payload` with `claimed_hash`), not the bare hash string.
Return the ledger link https://ledger.ainumbers.co/ so a human can re-verify without contacting us.
PII rule: All inputs are processed locally in your browser. No data is transmitted. Do not enter real personal data — use synthetic or anonymised inputs only.
Open the tool with the sample prefilled: https://ainumbers.co/chaingraph/art-339-compute-gross-to-net.html#p=v1.H4sIAAAAAAAA_wG4AEf_eyJ0YXhfeWVhciI6IjIwMjYiLCJncm9zc193YWdlc19wZXJfcGVyaW9kIjo1MDAwLCJmZWRlcmFsX3dpdGhob2xkaW5nX3Blcl9wZXJpb2QiOjAsInByZXRheF9yZWR1Y2VzX2ZpY2FfYW5kX2ZpdCI6MCwicG9zdF90YXhfb3RoZXJfZGVkdWN0aW9ucyI6MCwieXRkX2ZpY2Ffd2FnZXNfYmVmb3JlX3BlcmlvZCI6MTgwMDAwfY02TGu4AAAA