Last updated 30 September 2026 — by Adrian Tan, SDM. Marketing guidance, not legal advice. Rules are taken from the Weights and Measures Act 1975, the Weights and Measures (Defences under Section 19) Regulations 2022 and circulars from the Weights and Measures Office as published in September 2026.
Most marketing compliance is about what a claim means. The weights and measures rules are about something more basic: the number and the unit next to it. A product page that says “12 oz”, a bar menu that sells “a pint”, a pack of frozen prawns labelled 500 g that holds 440 g of prawns and 60 g of ice. None of these looks like a legal risk to the person who wrote it. In Singapore each one can be an offence.
The Weights and Measures Act 1975 does something few marketers expect. It names advertisements directly. Section 18 makes it an offence to use a non-metric unit “on any package, or in any price list or advertisement or otherwise” when advertising or displaying goods for sale. Section 19 makes it an offence to misrepresent the quantity of goods, or to sell a package holding less than it says. Since 1 July 2025 the Act has been run by the Competition and Consumer Commission of Singapore (CCCS), which also enforces the consumer protection law.
This guide explains the metric rule and its one safe harbour, how quantity claims and packages are tested, what the 2026 enforcement focus is, how the rules apply to online listings, menus and property ads, and a checklist for anyone writing product copy for the Singapore market.
Who enforces the Act now
Until 2025 the Weights and Measures Office (WMO) sat within Enterprise Singapore. That changed in 2025. The Competition (Amendment) Bill, passed in April 2025, moved legal metrology and consumer product safety from Enterprise Singapore to CCCS. Section 29(1) of the Act now reads: “The Commission is responsible for the administration of this Act.” The change took effect on 1 July 2025, and the WMO now describes itself as an office of the Commission.
That matters for marketers because it puts quantity claims in the same regulator’s hands as misleading-claims enforcement under the Consumer Protection (Fair Trading) Act. The agency that reads your price and your “free gift” wording now also reads your grams and millilitres.
The metric rule: section 18
Section 18(1)(d) is the provision that names advertising. It is an offence for anyone, in the course of trade or business, to use, “whether on any package, or in any price list or advertisement or otherwise, any unit of a weight or measure other than a weight or measure of the metric system, in advertising, displaying, or exposing goods for sale.” Section 18(1)(a) separately covers any contract or dealing made by reference to a non-metric measure.
The Act’s lawful units are listed in its First Schedule, and they are all metric: kilometres, metres, centimetres and millimetres; hectares, ares and square metres; cubic centimetres, litres and millilitres; tonnes, kilograms, grams and milligrams; and the metric carat, which is limited to precious stones and pearls. Section 6(1) says a person “must not use for trade any unit of measurement” not in that Schedule. The traditional hoon, chee, tahil and kati survive in the Third Schedule, but only for transactions that regulations specifically allow.
The safe harbour: metric first, and larger
Section 18(2) gives the one route for non-metric units. The ban in section 18(1)(d) does not apply to goods displayed or exposed for sale by retail, or to their packages, where the non-metric unit “is additional to” a metric one and its figures are marked “no larger than those of that metric weight or measure”.
So “500 g (17.6 oz)” is fine. “17.6 oz” on its own is not, and neither is a design that makes the ounce figure the headline and the grams a footnote. Imported goods are where this goes wrong most often: a US or UK product whose front-of-pack says “16 FL OZ” in large type, with the metric figure small or missing, fails the test as it stands.
Menus and price lists
The regulator has applied the rule to menus. A circular issued in November 2020 told businesses to make sure the units “on any package, price list or advertisement” are metric. It used the pint as its example: if “pint” is used, it “must be accompanied by the equivalent capacity” in metric, such as 568 ml, “on its price list/menu/advertisements”. A later circular of 15 August 2024 reminded liquor suppliers that they must use metric units.
The same circular also gave a short-measure example that applies to any drinks business. A kiosk that lists a 400 ml cup but serves less “is guilty of an offence”. If your menu board, delivery-app listing or Instagram post names a size, the drink has to match it.
Pizza in inches, screens in inches and TVs in inches are the everyday cases people ask about. The Act makes no exception for them. The cautious approach is to lead with the metric size, for example “30.5 cm (12-inch) pizza”, and treat the inch figure as secondary. We did not find any published enforcement against inch-sized pizzas or screens, so this is a risk to manage rather than a known enforcement priority.
Quantity claims: section 19
Section 19 deals with the amount rather than the unit. It contains several separate offences.
- Short delivery. Delivering “a lesser quantity than that purported to be sold” is an offence (s 19(1)).
- Misrepresenting quantity. Making “any misrepresentation either by word of mouth or otherwise as to the quantity of the goods” when exposing or offering them for sale is an offence (s 19(2)(b)). A product page, ad or social post is “otherwise”.
- Short packages. Selling a package that holds less than its stated quantity is an offence (s 19(3)), including catch-weight goods priced by actual weight (s 19(4)).
- Net, not gross. Under s 19(7), a statement of weight means net weight “unless otherwise expressed”. Packaging does not count towards the number on the label.
How much shortfall is allowed
No production line fills every pack exactly. The Weights and Measures (Defences under Section 19) Regulations 2022, in force since 21 November 2022, set how much individual packages may fall short before they count as “non-standard”, and when a package is so short that it is “inadequate”. A lot of packages passes only if the number of non-standard packages in a sample is within the allowed number and there are no inadequate packages at all. The allowed shortfall per package depends on the stated quantity.
| Stated quantity (g or ml) | Tolerable shortfall per package |
|---|---|
| Up to 50 | 9% of the stated quantity |
| 50 to 100 | 4.5 g or ml |
| 100 to 200 | 4.5% |
| 200 to 300 | 9 g or ml |
| 300 to 500 | 3% |
| 500 to 1,000 | 15 g or ml |
| 1 kg to 10 kg | 1.5% |
| 10 kg to 15 kg | 150 g or ml |
| Over 15 kg | 1% |
For length there is no allowance up to 5 metres and 2% above it. For area it is 3%. For goods sold by count there is no allowance up to 50 items and 1% above. Goods that lose moisture over time (the Regulations call them desiccating goods) are tested on an average-quantity basis set out in regulation 4.
Those tolerances are a defence for honest manufacturing variation. They are not a margin to design into a product. A 500 g pack that is always filled to 486 g is under-filling by design, and the defence exists for random variation, not a deliberate shortfall.
The 2025 and 2026 enforcement focus
The WMO’s recent circulars show where attention is going. On 14 May 2026 it issued a circular on accurate quantity declarations for pre-packaged goods. It said net quantity “must reflect the actual product weight, excluding all packaging”, and that ice glaze must be left out for frozen food. Its 2025 surveillance had found frozen seafood labelled heavier than its contents, which “led to corrective actions and enforcement measures”. For 2026 it said surveillance is widening to “a broader range of food staples”. Infringers “can face fines of up to $2,000”.
That follows a run of earlier circulars on the same theme: prepacked frozen seafood in June 2024, frozen glazed seafood in April 2025, and a general reminder on accurate quantity declarations in April 2023. The WMO’s guidance for sellers of pre-packaged goods is blunt: “It is an offence to supply PPGs with quantities less than the quantity stated on the package or label”, and the net content should be stated in metric units.
We did not find named court prosecutions for short weight in 2024 to 2026 that we could verify, so we do not cite any. The published enforcement story is surveillance, corrective action and fines at the level the Act allows.
The penalties
| Offence | Section | Maximum penalty |
|---|---|---|
| Delivering less than sold; misrepresenting quantity | s 19(1), s 19(2) | $5,000 fine, 3 months’ jail, or both |
| Non-metric units on a package, price list or ad | s 18 | $2,000 fine |
| Selling a package short of its stated quantity | s 19(3) | $2,000 fine |
| Composition of any offence | s 33 | Up to $2,000 |
The amounts are modest next to some regimes. The real cost is usually elsewhere: a recall or relabelling of stock, a delisting from a marketplace, and the reputational hit of a “short-weight” story in the press. And because CCCS now runs both this Act and the Consumer Protection (Fair Trading) Act, a quantity misstatement that also misleads consumers can be looked at under both.
Online listings, delivery apps and marketplaces
The Act was written before e-commerce, and we found no WMO guidance written specifically for online sellers. But section 18(1)(d) covers any “advertisement or otherwise”, and section 19(2) covers misrepresentation “by word of mouth or otherwise”. Nothing in either wording excludes a product page, a marketplace listing or a delivery-app menu. The sensible assumption is that online listings are covered.
In practice, the problems online tend to come from three places.
- Imported listings. Product data pulled from an overseas supplier’s feed often arrives in ounces, pounds, inches or US fluid ounces. The listing title and attributes need a metric figure first.
- Size variants. A drop-down offering “Small / Medium / Large” with no quantity is not a quantity claim. A drop-down offering “8 oz / 12 oz / 16 oz” is, and it needs metric equivalents.
- Old images. Pack shots showing a previous, larger fill after a pack change are a quantity misrepresentation risk. Update the image when the pack changes.
These are also conversion issues. Shoppers comparing products on a marketplace compare by grams and millilitres, and a listing that makes them convert units loses the comparison. Our guide to e-commerce conversion rate optimisation covers product page structure, and the Trade Descriptions Act guide covers the separate rules on product descriptions, origin claims and the SAFETY Mark.
Shrinkflation and unit pricing
Shrinkflation, selling less product at the same price, is not an offence in itself in Singapore. What the law requires is that the stated quantity is accurate and in metric units. If a pack shrinks from 500 g to 450 g and says 450 g, it complies with the Weights and Measures Act, whatever shoppers think of it.
Unit pricing, showing the price per 100 g or per litre, is not mandatory. CCCS and the Consumers Association of Singapore (CASE) announced a unit pricing pilot on 15 March 2025 at FairPrice, Cold Storage, Giant, Sheng Siong and Prime, covering rice, meat, eggs, cooking oils, fruit and vegetables. CASE’s president called unit pricing “a useful tool to address shrinkflation”. In a written reply on 7 July 2026, MTI did not make unit pricing compulsory. It said the pilot would be expanded to more outlets, including online, and pointed to the Consumer Protection (Fair Trading) Act as the tool for misleading representations.
For marketers, two practical points follow. Do not describe a smaller pack as “new” or “improved” in a way that hides the change, because that is a misleading-claims issue even if the grams are right. And if you sell groceries online, expect unit pricing to become a norm on the major platforms, so it is worth building a price-per-unit field into your product data now.
Property floor areas: sq m and sq ft
Singapore property is still commonly advertised in square feet. The National Library’s history of metrication notes that property ads “still cite areas in square feet”, while HDB uses square metres. The question is whether that is lawful under section 18.
We found no guidance or enforcement against square-foot property ads, so the position is untested. The Act has no property exemption, and section 18(1)(a) catches dealings “in relation to any matter, work, goods or other thing” made by a non-metric measure. On the other hand, the section 18(2) safe harbour is written for goods sold by retail, not property. The Council for Estate Agencies’ advertising guidelines require ads to “accurately describe the property” but do not specify a unit, and their own sample ad uses square metres.
The cautious approach for developers and agents is to lead with square metres and give square feet as a secondary figure. It costs nothing, it matches HDB’s usage, and it removes the question. Property marketing has other rules that matter more in practice. See our guides to digital marketing for property and to advertising short-term rentals.
A checklist for product copy and labels
- Metric always appears. Every quantity on packs, product pages, menus, price lists and ads has a metric figure.
- Metric leads. Any non-metric unit is additional and set no larger than the metric figure.
- Net, not gross. The stated weight excludes packaging, and for frozen food excludes ice glaze.
- Fill to the label. Set fill targets at or above the stated quantity. Tolerances are for random variation only.
- Check imports. Relabel or sticker imported goods whose front-of-pack leads with ounces or fluid ounces.
- Match the menu to the cup. If a drink size is stated in millilitres, the serve must match it.
- Clean the feed. Convert supplier product data to metric before it reaches your store or marketplace listing.
- Update images. Change pack shots when the pack size changes.
- Be straight about downsizing. A smaller pack must say so accurately, and should not be promoted in a way that hides the change.
Quantity is one line in a wider set of online selling rules. For the rest, see our list of legal requirements for Singapore websites. Food businesses should also read our guide to food advertising claims, and appliance sellers our guide to energy label advertising rules. Our Black Friday e-commerce guide covers how to prepare listings for the peak season, when catalogue errors multiply.
Some product categories carry their own advertising law on top of the metric rules. Retailers of e-scooters, e-bikes and mobility scooters, for example, commit an offence just by displaying or advertising a non-compliant device. Our guide to selling e-scooters, e-bikes and PMDs in Singapore sets out those rules.
Frequently asked questions
Can I advertise products in ounces or inches in Singapore?
Only alongside a metric unit. Section 18 of the Weights and Measures Act makes it an offence to use non-metric units on a package, price list or advertisement for goods for sale. For retail goods, a non-metric unit is allowed only if it is additional to the metric one and its figures are no larger.
Can a bar in Singapore sell beer by the pint?
Yes, if the menu also gives the metric equivalent. The regulator’s 2020 circular said a pint used on a price list, menu or advertisement must be accompanied by the equivalent capacity in metric, such as 568 ml, and the serve must match the stated quantity.
What is the penalty for short-weight packaging in Singapore?
Selling a package holding less than its stated quantity carries a fine of up to $2,000. Delivering less than was sold, or misrepresenting quantity, carries up to $5,000, three months’ jail, or both. The WMO’s May 2026 circular on pre-packaged goods cites fines of up to $2,000.
Does ice glaze count towards the weight of frozen seafood?
No. The Weights and Measures Office says net quantity must reflect the actual product weight, excluding all packaging, and that ice glaze must be excluded for frozen food. Its 2025 surveillance found frozen seafood labelled heavier than its contents.
Is unit pricing mandatory in Singapore?
No. CCCS and CASE began a voluntary unit pricing pilot at major supermarkets in March 2025, and in July 2026 MTI said it would be expanded, including online, without making it compulsory.
Who enforces the Weights and Measures Act in Singapore?
Since 1 July 2025, the Competition and Consumer Commission of Singapore (CCCS), through its Weights and Measures Office. The function was transferred from Enterprise Singapore under the Competition (Amendment) Act passed in April 2025.
The takeaway
The Weights and Measures Act is one of the few Singapore laws that names advertisements in its text. For marketers it comes down to two rules. Every quantity needs a metric unit, with any other unit secondary and no larger. And every quantity has to be true, net of packaging, ice and anything else that is not the product. CCCS now runs both this Act and the consumer protection law, and its 2026 surveillance is widening across food staples, so product data, labels and menus are worth checking now.
Our web design and e-commerce team builds product pages and data feeds with compliance built in, and you can see how we report results in our client case studies. For the wider picture, start with our complete guide to web design in Singapore and our guide to e-commerce marketing in Singapore.
