Free forever for ethanol producers

45Z carbon intensity, in plain sight.

An open application and API that runs the USDA FD-CIC and T-DISC tools inside your 45Z credit workflow — every input, every factor, every result visible and reproducible. No license. No paywall. No black box.

$0Cost to use, always
100%Auditable calculation trail
RESTAPI + web app
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The tools

Two USDA tools. One streamlined workflow.

Open45Z wraps the USDA calculators your 45Z paperwork depends on, so feedstock data flows from the field to your fuel carbon intensity score without re-keying spreadsheets.

USDA · FD-CIC

Feedstock Carbon Intensity Calculator

Turn farm-level practices — tillage, nitrogen management, cover crops — into a feedstock carbon intensity value for the corn you buy, with each assumption surfaced next to the number it produced.

USDA · T-DISC

T-DISC integration

Run T-DISC alongside FD-CIC in the same session and carry its outputs straight into your 45Z calculation, with the same inputs, versioning and export formats.

Plant-level view

Aggregate supplier-level feedstock scores into a facility-level result you can defend.

Audit-ready exports

One-click CSV and JSON bundles with inputs, tool versions and timestamps for your records.

Built for your stack

Pull results into your ETRM, LIMS or compliance system with a documented REST API.

Transparency

If you can't check it, you can't claim it.

Tax credits live and die on documentation. Open45Z is designed so that anyone — your team, your auditor, your lender — can follow the math.

  • Open source code — read exactly how inputs reach each USDA tool.
  • Version-pinned runs — every result records the tool version used.
  • Reproducible results — same inputs, same outputs, every time.
  • No hidden fees or upsells — no accounts gated behind a sales call.
Free

for every ethanol producer, every plant, every run.

Workflow

From the field to the 45Z filing.

Collect

Upload supplier and farm-practice data, or enter it directly.

Calculate

Run FD-CIC and T-DISC with a single request.

Review

Inspect every intermediate value and flag exceptions.

Export

Hand clean records to your tax and compliance team.

API

One endpoint away from automation.

Send feedstock and facility data, get back scores with the full calculation trail. Use the web app for one-offs or the API for the whole supply book.

# illustrative example — final routes & fields will be in the docs curl -X POST https://api.open45z.org/v1/calculate \ -H "Content-Type: application/json" \ -d '{ "tools": ["fd-cic", "t-disc"], "feedstock": "corn", "county": "Story, IA", "practices": { "tillage": "no-till", "cover_crop": true } }'
FAQ

Good questions.

Is it really free?

Yes. There is no subscription, per-run fee or paid tier for the core application and API.

Is this an official USDA or Treasury site?

No. Open45Z is an independent project that runs publicly available USDA tools. It is not affiliated with or endorsed by USDA, the Treasury Department or the IRS.

Does it replace tax advice?

No. Results support your 45Z documentation, but eligibility and filing positions should be confirmed with your tax advisor and current Treasury guidance.

What happens to my data?

Your inputs are used only to run the calculations you request. Data handling details will be published in plain language alongside the source code.

Make your 45Z math something everyone can see.

Free, open and ready for your next compliance cycle.