COA reading tool

THCA to Total THC Calculator

Enter THCA and delta-9 THC results from the same laboratory report, using the same unit for both. The calculator applies the standard 0.877 molecular-weight conversion and shows every step.

What the result means

Formula: delta-9 THC + (THCA × 0.877).

The 0.877 factor adjusts for the molecular-weight difference between THCA and THC. It is a mathematical estimate of potential total THC—not a prediction of real-world conversion.

Before you calculate

Use values from the same COA and the same sample.
Do not mix percent with mg/g.
Do not replace “ND” or “<LOQ” with zero unless the lab explains that treatment.
Check the report’s own method, notes, reporting limits, and rounding.

For a full explanation, read Total THC and THCA: How the Calculation Works. You can also review our guide to reading a hemp COA.

Educational arithmetic only. This tool does not determine legal status, regulatory compliance, safety, impairment, or an appropriate amount to consume. Laws and laboratory methods can differ.