27 CFR 4.37 governs how the net contents of wine must be declared on the label, and it works hand in hand with the container rules in Subpart H of Part 4 — the standard-container specifications of § 4.71 and the authorized standards of fill in § 4.72. Together they control both what the label says and what volumes a bottler may fill at all. Net contents is mandatory information under § 4.32(b), may appear on any label on the container, and is subject to the type size minimums of § 4.38.

The Net Contents Statement (§ 4.37(a))

Net contents must be stated in the metric system of measure. For wine filled to a standard of fill prescribed in § 4.72, the statement must appear in the same manner and form as set forth in the standard of fill — "750 mL," "1.5 liters," and so on. For wine in a container size with no prescribed standard of fill (in practice, the even-liter sizes above 3 liters under § 4.72(b)):

• More than one liter: state net contents in liters and decimal portions of a liter, accurate to the nearest one-hundredth of a liter

• Less than one liter: state net contents in milliliters (ml)

Placement is flexible: net contents is "any label" information under § 4.32(b), so it may appear on the front, back, neck, or strip label. Whatever label carries it, the statement must meet the § 4.38 minimum type sizes — at least 2 mm on containers over 187 mL and 1 mm on containers of 187 mL or less — on a contrasting background, readily legible under ordinary conditions.

U.S. customary measures (fluid ounces, quarts) may not substitute for the metric statement. Under § 4.37(b), a U.S. equivalent may be shown in addition to the metric statement, and the regulation prescribes the exact conversions — for example, 750 mL is shown as 25.4 fl. oz., 355 mL as 12.0 fl. oz., and 3 liters as 101 fl. oz. Equivalents under 100 fluid ounces are stated to the nearest tenth of an ounce; 100 fluid ounces or more, to the nearest whole ounce.

Authorized Standards of Fill (§ 4.72)

A wine container may only be filled to an authorized standard of fill. After the amendments finalized in T.D. TTB-200 (January 2025), § 4.72(a) authorizes 25 standards of fill for wine:

Under § 4.72(b), wine may also be bottled in containers larger than 3 liters if filled and labeled in quantities of even liters (4 liters, 5 liters, 6 liters, and so on) — those sizes are open-ended rather than enumerated.

The list has grown in two waves. TTB first added 200 mL, 250 mL, and 355 mL (the standard can sizes) effective from a December 2020 final rule (T.D. TTB-165), and then the January 2025 final rule added a further batch of wine sizes — including 180 mL, 300 mL, 330 mL, 360 mL, 473 mL, 550 mL, 568 mL, 600 mL, 620 mL, 700 mL, 720 mL, 1.8 L, and 2.25 L — and removed container-type distinctions, so a size like 355 mL is no longer restricted to cans. The additions accommodate international formats (700 mL and 720 mL align with spirits and sake conventions; 568 mL is the imperial pint) and the canned wine market (473 mL is the 16 oz can). Any size not on the list and not an even-liter size above 3 liters — a 650 mL bottle, for instance — may not be used for wine subject to Part 4.

The Blown, Etched, or Marked Container Exception (§ 4.37(c))

Net contents need not appear on any label if they are permanently marked in the container itself — blown, etched, sand-blasted, marked by underglaze coloring, or otherwise permanently marked by a method approved by TTB — on the sides, front, or back of the bottle. The marking must be plainly legible under ordinary circumstances and must not be obscured in any manner. Many glass suppliers mold "750 ml" into the base or lower sidewall of standard bottles precisely so the label artwork need not carry the statement; if you rely on this exception, confirm the molded figure is actually legible on the finished, labeled bottle.

Headspace and Fill (§ 4.71)

The standard-container rule at § 4.71(a) adds physical fill requirements. The container must not be made or formed so as to mislead the purchaser — a container whose actual capacity is substantially less than its apparent capacity on visual examination is noncompliant irrespective of a correct net contents statement. It must be filled to an authorized standard of fill, and headspace (the empty space between the top of the wine and the top of the container) is capped:

Fill Tolerances and Shortages (§ 4.37(d), (e))

The net contents statement must indicate exactly the volume of wine in the container, subject to three narrow tolerances in § 4.37(d): discrepancies due exclusively to filling errors occurring in compliance with good commercial practice; discrepancies due exclusively to unavoidable variations in container manufacturing capacity; and losses from ordinary and customary evaporation under varying atmospheric conditions. The reasonableness of any discrepancy is determined on the facts of each case — there is no fixed numeric underfill allowance in the wine rule. Section 4.37(e) adds that unreasonable shortages in some containers may not be offset by overages in others in the same shipment; averaging across a lot does not cure short-filled bottles.

How Truli Helps with Net Contents Compliance

• Standard of fill validation: Truli checks the declared net contents on every wine label against the current § 4.72 list, including the sizes added in the January 2025 rule, and flags unauthorized volumes before COLA submission

• Format checks: Truli verifies the statement uses metric units in the prescribed form, and that any U.S. equivalent matches the § 4.37(b) conversion table

• Cross-label consistency: Truli compares net contents across front label, back label, carton, and marketing copy so a 750 mL label never ships with 25 oz e-commerce copy

• Type size screening: Truli flags net contents statements that appear below the § 4.38 minimum type size for the container

Related Regulations

• 27 CFR Part 4 — TTB Wine Labeling Requirements — The full wine labeling framework this section belongs to

• 27 CFR 4.32 — Mandatory Wine Label Information — Where net contents fits among the required label elements

• 27 CFR 4.36 — Wine Alcohol Content Statements — The companion mandatory statement with its own format rules

• 27 CFR 4.38 — Wine Label Format, Legibility, and Type Size — The type size minimums that apply to the net contents statement

• 27 CFR Part 16 — Health Warning Statement — The GOVERNMENT WARNING required on the same container

Frequently Asked Questions

Can I sell wine in a 12 oz (355 mL) can?
Yes. 355 mL is an authorized standard of fill under § 4.72(a), and since the January 2025 amendments the size is available for any container type, not just cans. Label it "355 mL" (the U.S. equivalent "12.0 fl. oz." may be added), and keep headspace within the 6 percent cap that applies at 187 mL or more.

Do I need "750 mL" printed on my label if it is molded into the glass?
No. Under § 4.37(c), net contents permanently blown, etched, or otherwise marked in the bottle satisfy the requirement, provided the marking is plainly legible under ordinary circumstances and not obscured — including by the label itself.

Is a 650 mL bottle legal for wine?
No. 650 mL is not among the 25 authorized standards of fill in § 4.72(a), and it is not an even-liter size above 3 liters under § 4.72(b). Wine subject to Part 4 may not be bottled in that size; the nearest authorized options are 620 mL and 700 mL.

A note from Truli: Truli is not a law firm, and this article does not constitute or contain legal advice or create an attorney-client relationship. When determining your obligations and compliance with respect to relevant laws and regulations, you should consult a licensed attorney.

Last updated: August 2026. Reflects 27 CFR 4.37 and 27 CFR 4.72 as of August 2026. Truli monitors TTB rulemaking and enforcement. Book a demo to see how.