16 CFR § 500.23 - Expression of net quantity of contents in SI Metric units.

---
identifier: "/us/cfr/t16/s500.23"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "16 CFR § 500.23 - Expression of net quantity of contents in SI Metric units."
title_number: 16
title_name: "Commercial Practices"
section_number: "500.23"
section_name: "Expression of net quantity of contents in SI Metric units."
chapter_name: "FEDERAL TRADE COMMISSION"
subchapter_number: "E"
subchapter_name: "RULES, REGULATIONS, STATEMENT OF GENERAL POLICY OR INTERPRETATION AND EXEMPTIONS UNDER THE FAIR PACKAGING AND LABELING ACT"
part_number: "500"
part_name: "REGULATIONS UNDER SECTION 4 OF THE FAIR PACKAGING AND LABELING ACT"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "15 U.S.C. 1453, 1454, 1455."
regulatory_source: "59 FR 1872, Jan. 12, 1994, unless otherwise noted."
cfr_part: "500"
---


# 500.23 Expression of net quantity of contents in SI Metric units.

(a) The selected multiple or submultiple prefixes for SI metric units shall result in numerical values between 1 and 1000, except that centimeters or millimeters may be used where a length declaration is less than 100 centimeters. For example, “1.96 kg” instead of “1960 g” and “750 mL” instead of “0.75 L”.

(b) The following symbols for SI metric units and none others may be employed in the required net quantity declaration:

centimeter—cm

cubic centimeter—cm 
<sup>3</sup>

cubic decimeter—dm 
<sup>3</sup>

meter—m

milligram—mg

liter—L or l

milliliter—mL or ml

square decimeter—dm 
<sup>2</sup>

cubic meter—m 
<sup>3</sup>

kilogram—kg

micrometer—µm

gram—g

millimeter—mm

square meter—m
<sup>2</sup>

square centimeter—cm
<sup>2</sup>

Symbols, except for liter, are not capitalized. Periods should not be used after the symbol. Symbols are always written in the singular form.