Statute Details
- Title: Metrication Act 1970
- Act Code: MA1970
- Full Title: An Act to introduce the use of the International System of Units in Singapore, to enable necessary modifications of legislation to be effected and for matters connected therewith.
- Type: Act of Parliament
- Commencement: [15 February 1971] (as stated in the Act)
- Current Version: “Current version as at 27 Mar 2026” (per the provided extract)
- Core Purpose: Establishes the International System of Units (SI) as legally valid in Singapore and provides mechanisms to adapt existing laws to metric references.
- Key Provisions: Section 3 (legal force of SI from 15 February 1971); Section 4 (Minister’s power to adapt written laws to SI); Section 5 (conversion of imperial/customary measures per Third Schedule); Section 6 (power to vary Schedules by Gazette notification); Section 7 (saving provisions).
- Schedules: First Schedule (basic units); Second Schedule (supplementary and derived units); Third Schedule (conversion rules/values); Fourth Schedule (units usable in conjunction with SI units).
What Is This Legislation About?
The Metrication Act 1970 is Singapore’s foundational statute for “metrication”—the legal adoption of the International System of Units (SI) as the standard system of measurement. In practical terms, it ensures that when legislation, contracts, technical specifications, and regulatory instruments refer to quantities (length, mass, capacity, etc.), the relevant units are anchored to SI rather than to older imperial or customary measurement systems.
The Act does more than declare SI to be the preferred system. It also anticipates that Singapore’s existing body of written law would contain references to non-metric units. Accordingly, it gives the Minister a structured power to adapt, alter, convert, or modify provisions in other written laws so that those laws can be expressed in SI terms. This is important for legal certainty: if different statutes use different measurement systems without a consistent legal framework, disputes can arise over interpretation, compliance, and enforcement.
Finally, the Act includes conversion and saving provisions. Section 5 provides for conversion of certain imperial standard units and local customary weights and measures into SI values according to the Third Schedule. Section 7 protects past acts from being challenged solely because they were done using non-SI units, and it preserves the legal force and validity of other systems of units lawfully used in Singapore.
What Are the Key Provisions?
Section 3: SI has legal force and validity from 15 February 1971. Section 3(1) is the Act’s central declaration. On and after 15 February 1971, the “system of units known as the International System of Units” has legal force and validity in Singapore. This means SI is not merely a policy preference; it is a legally recognised measurement system for purposes of Singapore law.
Section 3(2) defines what constitutes SI for the purposes of the Act. It includes: (a) the basic units in the First Schedule; (b) supplementary and derived units in the Second Schedule; and (c) units that may be used in conjunction with SI units in the Fourth Schedule. The inclusion of the Fourth Schedule is significant because it recognises that certain non-basic units may still be used alongside SI units, subject to the Act’s framework.
Section 2: Interpretation and recognition of “SI”. Section 2(1) defines “International System of Units” by reference to the Schedules, and Section 2(2) recognises the abbreviation “SI” as a legal reference. For practitioners, this matters because legal instruments often use “SI” shorthand; the Act confirms that “SI” is not informal jargon but a recognised legal reference.
Section 4: Minister’s power to adapt written laws to SI. Section 4(1) empowers the Minister, by order, to adapt, alter, convert, or modify provisions in any written law relating to appropriate departments and subjects. The purpose is to replace references to units other than metric units with references to SI units that are either (a) equivalent, or (b) approximations that the Minister considers desirable to express enactments in “convenient terms.”
This provision is a practical legislative tool. It acknowledges that exact equivalence may not always be feasible or necessary in legal drafting, and it authorises approximations where appropriate. However, the power is not open-ended: it is tied to the purpose of replacing non-metric references with SI references, and it is exercised through orders that must be published in the Gazette. For lawyers, the Gazette publication requirement is a key procedural safeguard and a marker for when adapted legal text takes effect.
Section 5: Conversion of imperial standard units and local customary measures. Section 5 provides that values expressed in terms of (a) imperial standard measures of extension (lineal, superficial, solid), weight, or capacity; or (b) the local customary system of weights and measures, may be converted into SI values in accordance with the Third Schedule. The wording “may be converted” indicates that conversion is permitted and governed by the Third Schedule, rather than requiring conversion in all contexts. In practice, this supports consistent conversion methodologies where older units appear in technical or regulatory contexts.
Section 6: Power to vary the Schedules. Section 6 allows the Minister, by notification in the Gazette, to add to, vary, or amend the Schedules as the Minister thinks fit. This is important because measurement standards and unit conventions can evolve. The Act therefore provides an administrative mechanism to keep the schedules aligned with contemporary SI usage without requiring frequent primary legislation.
Section 7: Saving provisions (no retroactive challenge; preservation of other lawful unit systems). Section 7(1) states that no act or thing done before the making of any order under Section 4 may be challenged only on the ground that it was done in a unit other than an SI unit. This protects reliance interests and prevents technical challenges based solely on measurement units used at the time.
Section 7(2) further provides that nothing in the Act affects the legal force and validity of any other system of units lawfully used in Singapore. This is a crucial limitation: SI is legally valid, but the Act does not necessarily abolish all other unit systems. Instead, it preserves lawful usage, which may include specialised industries, scientific contexts, or transitional arrangements.
How Is This Legislation Structured?
The Act is structured as a short, enabling statute with seven sections and multiple schedules. The main operative provisions are concentrated in Sections 3 to 6, supported by interpretive and saving provisions.
Sections 1 and 2 deal with the short title and interpretation. Section 3 establishes SI’s legal force and defines its components by reference to the Schedules. Section 4 provides the Minister’s power to adapt other written laws to SI references, including the use of equivalent or approximated SI values. Section 5 addresses conversion of imperial and local customary measures into SI values via the Third Schedule. Section 6 authorises updates to the Schedules through Gazette notifications. Section 7 contains saving provisions to protect past acts and preserve other lawful unit systems.
The First, Second, Third, and Fourth Schedules perform the technical work of specifying the units and conversion values. This legislative design is typical for measurement standards: the Act provides legal authority and mechanisms, while the schedules contain the detailed unit definitions and conversion rules.
Who Does This Legislation Apply To?
The Metrication Act 1970 applies broadly to Singapore’s legal and regulatory environment because it confers legal force on SI “in Singapore” and authorises adaptation of “any written law.” While the Act does not itself impose a direct compliance duty on private parties in the way a licensing statute might, its effect is pervasive: where laws, regulations, or official instruments specify quantities, SI units are the legally recognised framework.
In practice, the Act affects: (1) government departments and regulators drafting or enforcing measurement-related rules; (2) regulated entities whose compliance depends on statutory or regulatory quantities; and (3) parties to contracts or technical documents that incorporate statutory measurement references. Section 7(2) also indicates that other unit systems may continue to be lawfully used, so the Act’s impact depends on what is “lawfully used” and how other instruments interact with SI.
Why Is This Legislation Important?
The Metrication Act 1970 is important because it provides legal certainty in a domain where measurement is foundational. Without a legal standard for units, disputes could arise over how to interpret statutory quantities—particularly in areas such as trade, engineering specifications, health and safety requirements, taxation or fees based on measured quantities, and regulatory thresholds.
From an enforcement and compliance perspective, Section 3’s legal force declaration reduces ambiguity: SI is the default legal system of units. Section 4’s adaptation power ensures that older laws can be brought into alignment with SI, preventing a fragmented legal landscape where some statutes refer to imperial units and others refer to metric units.
For practitioners, the saving provisions in Section 7 are equally significant. They mitigate litigation risk by preventing retroactive challenges based solely on the unit system used before SI-related adaptations were made via Section 4 orders. This is particularly relevant in disputes involving historical compliance, contractual performance, or regulatory actions taken before specific adaptation orders.
Finally, the Minister’s power to vary schedules (Section 6) means that the technical content of SI references can be updated through Gazette notifications. Lawyers should therefore monitor Gazette updates and the current consolidated version of the Act to ensure that the unit definitions and conversion values used in legal arguments reflect the latest schedule content.
Related Legislation
- Metrication Act 1970 (consolidated/revised editions, including the 2020 Revised Edition as indicated in the provided extract)
- Any written laws amended by orders made under Section 4 of the Metrication Act 1970 (to replace non-metric unit references with SI equivalents/approximations)
- Gazette notifications issued under Section 4 and Section 6 (adaptation orders and schedule amendments)
Source Documents
This article provides an overview of the Metrication Act 1970 for legal research and educational purposes. It does not constitute legal advice. Readers should consult the official text for authoritative provisions.