Cannabis Education

TAC vs THC: How to Read a New Jersey Cannabis Label

TAC counts every cannabinoid a lab measured; THC is the one New Jersey labels single out. How NJ calculates total THC, turns % into mg, and what to check.

9 min read October 5, 2026 West Orange, NJ

X Facebook LinkedIn

Close-up of a flowering cannabis bud covered in frosty white trichomes, shown for illustration — Trichomes on a cannabis flower. Photo by Psychonaught, released into the public domain (Wikimedia Commons). For illustration only; not a product sold at The Library.

Quick answer

THC is the strength number. TAC is THC plus everything else.

TAC (total active cannabinoids) adds up every cannabinoid the lab measured in a batch. THC on a New Jersey label is total THC, worked out with one state formula for every product. TAC is always equal to or higher than THC. When you compare two products, compare the THC line; read the gap between TAC and THC as how much CBG, CBD, CBN and other cannabinoids came along with it.

TAC

All measured cannabinoids

Not defined in New Jersey's labeling rules

THC

THCA x 0.877 + delta-9

The NJ-CRC total THC formula

Checked

October 5, 2026

Rules and The Library's online menu

What TAC and THC Look Like on The Library's Menu

The Library's online menu lists both numbers side by side for many products. These three were on the menu on October 5, 2026. The last two columns are our arithmetic: how many percentage points separate TAC from THC, and what share of the measured cannabinoids is something other than THC.

TAC and THC listed on The Library's online menu, October 5, 2026
Product	TAC	THC	Gap	Not THC
Grasshopper Gelato SherbetFlower, 3.5 g	19.49%	17.31%	2.18 points	11.2% of TAC
Black Bag OG Gas FacePre-rolls, 3-pack (1 g)	25.01%	21.75%	3.26 points	13.0% of TAC
Loud Stash Hella JellyAll-in-one vape, 2 g	94.87%	92.75%	2.12 points	2.2% of TAC

Two things stand out. On the flower and the pre-rolls, 11% to 13% of the measured cannabinoids are something other than THC. On the vape oil, almost all of it is THC. A higher TAC with the same THC does not mean more THC; it means more of the other cannabinoids.

Menus change daily and each batch tests differently. These figures describe the batches listed on October 5, 2026, not what is on the shelf today. The label on the package you buy is the record for your batch.

What TAC Means, and Why New Jersey Rules Never Mention It

New Jersey tells producers which cannabinoids must appear on the label. Under the Cannabis Regulatory Commission's February 2025 labeling guidance, the cannabinoid profile must show total THC, total CBD, total CBG and CBN. Total CBC, total THCV and total CBDV may also be listed. TAC is not on that list. It is a summary figure that labs and brands add on their own.

Because no rule defines it, TAC is not always calculated the same way. SC Labs, a cannabis testing lab, publishes two different totals on its certificates of analysis: "Total Cannabinoids," where each acid form such as THCA is first multiplied by 0.877, and "Sum of Cannabinoids," where every measured cannabinoid is added as it is. Run the same batch both ways and you get two different numbers.

One illustrative lab panel

THCA22.00%
Delta-9 THC0.60%
CBGA1.20%
CBG0.10%
CBDA0.10%
CBN0.05%

Example numbers for the arithmetic, not a real product.

Three totals from the same panel

Total THC (NJ formula): 22.00 x 0.877 + 0.60 = 19.89%
TAC, acids converted: 19.894% THC + 1.154% CBG + 0.088% CBD + 0.050% CBN = 21.19%
TAC, added as measured: every line in the panel added together = 24.05%

Same flower, a 2.86-point difference in TAC depending on the method. Only the THC figure follows one state formula.

How to use TAC

Compare TAC only between products from the same brand or tested by the same lab, and treat it as a description of the whole cannabinoid mix. For THC content, read the THC line. New Jersey's edible rules also talk about "active THC" in milligrams; that is THC only, not TAC.

How New Jersey Calculates Total THC

Total THC = (THCA x 0.877) + delta-9-THC

NJ Cannabis Regulatory Commission, Packaging and Labeling Guide

In flower, most of the THC potential is usually measured as THCA, the acid form. Heat turns THCA (C22H30O4) into THC (C21H30O2) by releasing carbon dioxide, so the molecule gets lighter. PubChem lists THC at 314.5 g/mol and THCA at 358.5 g/mol; 314.5 divided by 358.5 is 0.877. That is why New Jersey multiplies THCA by 0.877 before adding the delta-9 THC already present. The same rule gives total CBD (CBDA x 0.877 + CBD) and total CBG (CBGA x 0.878 + CBG).

Two more details from the Commission's testing guidance explain why flower numbers look the way they do. Labs report flower potency on a dry-weight basis, dividing by the moisture left in the sample. And before potency testing, flower must pass a water activity limit of 0.65. So a percentage on a jar is the share of dried plant material, not of whatever humidity the jar holds today.

For the chemistry behind THCA, including how much converts in practice, read The Library's THCA guide.

Turn a Label Percentage Into Milligrams

One percent of one gram is 10 mg. Multiply grams by the percentage and by 10 to get milligrams in the package. The results below are what the package contains, not a serving size.

Milligrams of cannabinoids in a package at common label percentages
Package	Label figure	In the package
Eighth of flower, 3.5 g	15% THC	525 mg THC
Eighth of flower, 3.5 g	20% THC	700 mg THC
Eighth of flower, 3.5 g	25% THC	875 mg THC
Pre-roll pack, 1 g total	21.75% THC	217.5 mg THC
Vape cartridge, 1 g	90% TAC	900 mg of cannabinoids
All-in-one vape, 2 g	92.75% THC	1,855 mg THC

Edibles skip the math because New Jersey labels them in milligrams. Under N.J.A.C. 17:30-11.5(d), each serving may contain no more than 10 mg of active THC and each package no more than 100 mg. On October 5, 2026, the edibles on The Library's menu were listed at 50 mg and 100 mg per package.

Lab tests on edibles may land between 90% and 110% of the claimed amount. The Commission's guidance updated August 12, 2026 says a label may not print more than 100 mg of active THC per package even when a lab result falls inside that range. If you see a number above 100 mg on an edible package, ask about it. For serving sizes, see the New Jersey edible dosing chart.

Compare THC across today's flower

The Library's flower page links to the live menu, where TAC and THC are listed for many items. Read the THC line first, then the gap.

Shop Flower Browse Full Menu

Every Line on a New Jersey Cannabis Label

The Commission's April 2024 Packaging and Labeling Guide lists what each package must carry. Here is what each line tells you as a shopper.

1
Who grew or made it
Name, address, license number and phone number of the cultivator and manufacturer.
2
Net weight and quantity
Flower packages sold to a retailer can hold any amount up to one ounce (28.35 g).
3
Batch, lot and tracking tag
A serial number, batch or lot number and bar code. A Metrc tag can satisfy this and the state tax-stamp rule.
4
Cannabinoid and terpene profile
In milligrams and as a percentage, for the whole item and for one serving, with total THC, total CBD, total CBG and CBN.
5
Chemotype
One of three state categories based on the THC-to-CBD ratio and total THC (see the table below).
6
How it was grown
Indoor, outdoor, soil-grown, hydroponic or aquaponic; whether all-organic materials were used; and any allowed pesticides, fungicides or herbicides applied.
7
Servings
Serving size and number of servings. Multi-serving packs must say "INCLUDES MULTIPLE SERVINGS" on the outside.
8
Ingredients and allergens
Any ingredient besides cannabis, a list of potential allergens, and whether the item needs refrigeration.
9
Extraction method
Since February 2025 the Commission encourages concentrate labels to name the solvent, such as butane, or a non-chemical process like heat and pressure.
10
Universal symbol and warnings
The New Jersey universal symbol, a 21+ statement, the poison control number 1-800-222-1222, and the driving and pregnancy warnings.

The three New Jersey chemotypes

Chemotype categories required on New Jersey cannabis labels
Label says	THC to CBD ratio	Total THC
High THC, Low CBD	Greater than 5:1	15% or more
Moderate THC, Moderate CBD	Between 5:1 and 1:5	5% to 15%
Low THC, High CBD	Less than 1:5	5% or less

A product that does not fit one of the three is labeled with the closest chemotype by its THC-to-CBD ratio. The flower and the pre-rolls in the menu table above are both over 15% THC.

Front-of-package warnings to expect

Above 40% total THC, which covers most vapes and concentrates: "This is a high potency product and may increase your risk for psychosis."
Edibles: "The intoxicating effects of this product may be delayed by two or more hours."
Vape devices: "This device has not been evaluated or approved by the Food and Drug Administration."

Wording as required by the NJ-CRC Packaging and Labeling Guide, in at least 10-point type.

Harvest, Packaging and Expiration Dates

Every New Jersey package carries a production or harvest date and an expiration date. For flower and most products, the expiration date can be no later than six months from the cultivation or manufacture date, unless the manufacturer has stability testing that supports a different date. Water-based liquid preparations kept between 36 and 46 degrees Fahrenheit are limited to 14 days.

So the harvest date tells you more about a jar than the expiration date does. Two eighths with the same THC percentage can sit at very different points in that six-month window. Once it is home, keep it in the original light-resistant package and see how to store cannabis properly.

Check a Label at The Library in West Orange

The Library is a licensed adult-use dispensary at 5 Washington Street in West Orange. The online menu shows TAC and THC for many products, and you can ask a budtender to show you the package label, harvest date and batch number before you pay.

Adults 21 and older need a valid government-issued photo ID. Order online for pickup or shop in store.

Shop Flower Get Directions

First time in a New Jersey dispensary? Read the first-visit guide and how much you can buy in New Jersey.

TAC vs THC: Frequently Asked Questions

What is TAC in weed?

TAC stands for total active cannabinoids. It is a lab summary that adds up the cannabinoids measured in a batch, such as THC, CBD, CBG and CBN, into one percentage. New Jersey's labeling rules do not define TAC, so labs and brands can calculate it in slightly different ways.

Is TAC the same as THC?

No. THC on a New Jersey label is total THC, calculated as THCA times 0.877 plus delta-9 THC. TAC includes total THC plus the other cannabinoids the lab measured, so TAC is always the same as or higher than THC. To compare how much THC two products contain, compare the THC line, not TAC.

Why is TAC higher than THC on my label?

The gap is the other cannabinoids the lab measured in the batch, such as CBG, CBD and CBN. On The Library's menu on October 5, 2026, the gap was 2.18 points on a flower (19.49% TAC, 17.31% THC), 3.26 points on a pre-roll pack and 2.12 points on an all-in-one vape.

What does 90% TAC mean on a vape?

It means about 90% of the oil's weight is cannabinoids. A 1 gram cartridge at 90% TAC holds about 900 mg of measured cannabinoids. The THC line tells you how much of that is THC.

How does New Jersey calculate total THC?

The New Jersey Cannabis Regulatory Commission's labeling guidance sets Total THC = (THCA x 0.877) + delta-9-THC. The 0.877 factor reflects the weight THCA loses when heat turns it into THC. Flower potency is reported on a dry-weight basis.

How many milligrams of THC are in an eighth?

Multiply the grams by the THC percentage and by 10. An eighth (3.5 g) labeled 20% total THC contains about 700 mg of total THC in the package. That is the amount in the package, not a serving size.

Can I see the label before I buy at The Library?

Yes. Ask a budtender at The Library, 5 Washington Street in West Orange, to show you the package label before you pay. The online menu shows TAC and THC for many items, but the label on the package you take home is the record for that batch.

Primary Sources and Date Reference

Rules, lab definitions and The Library's menu were checked on October 5, 2026. Follow the Commission's links for the newest versions.

Gap and milligram figures on this page are arithmetic on the cited numbers. The illustrative lab panel is an example, not a product.

This article is educational and is not medical or legal advice. Product availability, batches and test results change. The Library is a licensed New Jersey cannabis retailer (License RE000228) serving adults 21 and older.

TLT

The Library Team

Cannabis Dispensary Experts

The Library of New Jersey

The Library team is dedicated to providing accurate, helpful information about cannabis products and New Jersey's cannabis industry. Our expert budtenders and educators contribute to every article.

Licensed DispensaryNJ Cannabis Regulatory CommissionProfessional BudtendersCannabis Educators

Published: October 5, 2026Updated: October 5, 2026

Indica vs Sativa: Your Complete Guide

First Time at a Dispensary? Complete NJ Guide

Cannabis Edibles Dosing Guide for Beginners

How Long Do Edibles Take to Kick In?

How to Store Cannabis Properly

Shop Cannabis Products

Premium buds

Gummies & treats

Pens & carts

Ready to smoke

Wax & shatter

Wellness products

Find a Dispensary Near You

Dispensaries Near Me West Orange Montclair Newark Bloomfield Livingston

Disclaimer: Cannabis products are for adults 21 and older only. Cannabis should be consumed responsibly. Do not drive or operate heavy machinery under the influence of cannabis. The effects of cannabis vary by individual. Start with a low dose and wait before consuming more. This content is for informational purposes only and does not constitute medical advice. The Library operates under NJ Cannabis Retail License RE000228. For questions about NJ cannabis regulations, visit the NJ Cannabis Regulatory Commission.