Total THC vs. Delta-9 THC: What It Means for Hemp Flower in 2026 (and How to Stay Compliant)

If you’ve ever read a hemp lab report and felt a little confused, you’re not alone.

Terms like Delta-9 THC, THCA, Total THC, LOQ, and measurement uncertainty show up on Certificates of Analysis (COAs) all the time—but most brands don’t explain what they actually mean.

In 2026, hemp regulations continue to evolve, and customers are paying closer attention to compliance than ever. Whether you buy hemp flower regularly or you’re just trying to make an informed purchase, understanding the difference between Delta-9 THC and Total THC is one of the most helpful things you can do.

Let’s break it down in simple terms.

What Does “0.3% THC” Actually Mean?

Under federal law, hemp is defined as Cannabis sativa L. (and its derivatives) containing no more than 0.3% Delta-9 THC on a dry weight basis.

That definition is the foundation of legal hemp in the U.S.—but it’s also where most confusion begins.

Why? Because many testing programs and state regulations don’t stop at Delta-9 THC. They also evaluate the product’s Total THC, which includes compounds that can convert into Delta-9 THC under heat.

So it helps to know what each term means before reading a COA.

Delta-9 THC vs. Total THC: The Difference

Delta-9 THC

Delta-9 THC is the cannabinoid most people associate with “THC.” It’s specifically named in the federal hemp definition.

A COA will often show Delta-9 THC as its own line item, usually listed in a percentage.

Total THC

Total THC is a compliance calculation used in many testing standards to estimate the total amount of THC that could be present after conversion.

This matters because hemp flower contains not only Delta-9 THC, but also THCA, which can convert into Delta-9 THC when heated.

In other words:

• Delta-9 THC is what the sample already contains in its active form

• Total THC reflects what could result after THCA converts under heat

What Is THCA (and Why Does It Matter)?

THCA stands for tetrahydrocannabinolic acid. It’s a naturally occurring cannabinoid found in raw hemp flower.

THCA is not the same compound as Delta-9 THC. But when heated, THCA can convert into Delta-9 THC. That’s why many hemp testing programs factor THCA into compliance evaluations.

This is one reason customers often see hemp flower with low Delta-9 THC but higher THCA numbers. It can look confusing at first—especially if the label says “hemp” but the lab report shows a large THCA percentage.

How Total THC Is Calculated (The COA Formula)

A common Total THC calculation used in hemp testing is:

Total THC = (THCA × 0.877) + Delta-9 THC

The 0.877 factor accounts for the molecular change that happens when THCA converts to THC. It’s a standard conversion used in analytical reporting and compliance calculations.

Example

If a COA shows:

• THCA: 10.00%

• Delta-9 THC: 0.20%

Then:

• THCA × 0.877 = 8.77%

• Total THC = 8.77% + 0.20% = 8.97% Total THC

This calculation doesn’t automatically determine whether a product is legal in every state—but it helps explain why Total THC is a major compliance focus in many hemp programs and regulated supply chains.

Why Some Hemp Rules Look Stricter Than the Farm Bill

Federal law defines hemp using Delta-9 THC.

But many state programs and hemp testing regulations use rules designed to prevent hot crops and ensure compliance based on how THC can develop or convert.

That’s why some programs require:

• post-decarboxylation testing (heating the sample as part of analysis), or

• Total THC calculations that include THCA conversion

Because hemp programs vary by state and enforcement can differ, it’s always important to check local regulations and only purchase from brands that prioritize transparent testing.

What Does “LOQ” Mean on a COA?

When you’re looking at a Certificate of Analysis, you may see values listed as:

• ND (Not Detected)

• < LOQ (Below the Limit of Quantitation)

LOQ stands for Limit of Quantitation—the smallest amount of a compound that a lab can accurately measure with confidence.

So if you see < LOQ, it typically means:

• the compound is too low to measure reliably

• it may be present in trace amounts, but not at a reportable level

This is one of the details that helps customers distinguish high-quality, transparent lab reporting from vague or incomplete COAs.

What Is “Measurement Uncertainty” (MU)?

Lab testing isn’t a perfect single number—it’s a measurement that includes a margin of error.

That margin is often called Measurement Uncertainty (MU).

MU matters most when products are close to a regulatory threshold. It helps regulators and licensed producers interpret results realistically, rather than treating small variations as absolute.

For customers, MU is another sign you’re looking at a legitimate lab report following established compliance standards.

How to Read a Hemp COA Like a Pro (Quick Checklist)

Before buying hemp flower—or comparing brands—here are the key things to look for:

✅ Batch-specific COA (not a generic lab report)
✅ Recent test date (within a year or so is preferred)
✅ Delta-9 THC listed clearly
✅ THCA listed clearly
✅ Total THC included or easy to calculate
✅ LOQ / ND values shown
✅ Lab name and certificate info included

The Bottom Line: Clear Testing Builds Real Trust

Delta-9 THC and Total THC are not the same thing, and understanding the difference helps you make more informed choices.

Federal hemp law focuses on Delta-9 THC, while many compliance programs account for THCA conversion through Total THC testing methods. That’s why lab reports can show multiple THC-related values—and why it matters to choose brands that explain what they’re selling.

At Plain Jane, the goal is simple:
clear sourcing, transparent testing, and straightforward information you can verify.

FAQ: Total THC vs. Delta-9 THC

Is Total THC the same thing as Delta-9 THC?

No. Delta-9 THC is a single compound. Total THC includes Delta-9 THC plus THC that could form from THCA conversion.

Why does THCA show up so high on hemp COAs?

Hemp flower naturally contains THCA, and it can appear as a larger percentage than Delta-9 THC on a lab report.

Does every state follow the same hemp testing rules?

No. Hemp compliance requirements can vary by state, and some states apply stricter standards than federal definitions.

What does “dry weight basis” mean?

It means the THC concentration is calculated based on the product’s weight excluding moisture content, which is the standard definition used in federal hemp law.

FDA Disclosure

These statements have not been evaluated by the Food and Drug Administration. This content is for informational purposes only and is not intended to diagnose, treat, cure, or prevent any disease.