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IS 965:1963 is the Indian Standard (BIS) for equivalent metric units for scales dimensions and quantities in general construction work. This standard provides guidance on equivalent metric units, scales, dimensions, and quantities used in general construction work. It was historically introduced to assist engineers, architects, and quantity surveyors in standardizing the transition from the imperial (FPS) system to the metric system for civil engineering drawings, estimates, and measurements.
Equivalent Metric Units For Scales Dimensions And Quantities In General Construction Work
Overview
Status
Current
Usage level
Rare
Domain
General — Building Construction Practices incl. Painting, Varnishing
! This code is rarely used for new designs but is highly useful for heritage conservation, renovations, or interpreting legacy construction drawings and property deeds drafted before the full adoption of the metric system in India.
! When converting drawing scales for modern CAD use, prefer rationalized metric scales (e.g., 1:50, 1:100) rather than exact mathematical equivalents of fractional imperial scales.
International Equivalents
Similar International Standards
IEEE/ASTM SI 10-2016Institute of Electrical and Electronics Engineers / ASTM International, USA
HighCurrent
American National Standard for Metric Practice
Provides comprehensive guidance and conversion factors for using the SI (metric) system, which is the core purpose of IS 965.
ISO 80000-1:2009International Organization for Standardization, International
MediumCurrent
Quantities and units — Part 1: General
Defines the International System of Units (SI), providing the foundational principles that IS 965 aimed to implement in India.
BS 6953:1988British Standards Institution, UK
HighWithdrawn
Specification for guide to the use of SI units in construction documents
Served the same transitional purpose as IS 965 by providing specific guidance for metrication within the UK construction industry.
A national standard providing rules for the implementation and use of the SI system in Canada, similar to IS 965's role in India.
Key Differences
≠IS 965 is a transitional document from 1963, designed to guide a one-time shift from Imperial to Metric units. Modern equivalents like IEEE/ASTM SI 10 are maintenance documents for an already established system.
≠IS 965 provides specific dimensional recommendations for Indian construction materials, such as a 'metric brick' size of 20cm x 10cm x 10cm. International standards typically provide conversion factors and rules, not region-specific product dimensions.
≠The Indian standard is a concise, all-in-one guide for its time. Modern international practice separates topics into more specialized standards (e.g., ISO 80000 for units, ISO 5455 for drawing scales, ISO 1006 for modular coordination).
≠IS 965 was written before the Newton was widely adopted in civil engineering for force calculations. It focuses on mass (kg, tonne) for weight, whereas modern standards like IEEE/ASTM SI 10 strictly differentiate between mass (kg) and force (Newton).
Key Similarities
≈The fundamental objective of IS 965 and its international counterparts is to promote the standardized use of the SI (metric) system to ensure clarity, consistency, and interoperability in construction.
≈All standards are based on the same core principles of the International System of Units, using the metre, kilogram, and second as base units.
≈The conversion factors between Imperial and SI units (e.g., 1 foot = 0.3048 metres) are identical across all standards, as they are based on international agreement.
≈The recommended derived units for common quantities like area (square metre, m²), volume (cubic metre, m³), and mass (kilogram, kg) are consistent across IS 965 and modern international standards.
Parameter Comparison
Parameter
IS Value
International
Source
Primary Length Unit
Recommends the metre (m) as the basic unit for civil engineering structures.
The metre (m) is the SI base unit of length.
ISO 80000-1
Recommended Drawing Scales (Layouts)
1:500, 1:200, 1:100
Recommended scales include 1:100, 1:200, 1:500 from the preferred series.
ISO 5455:1979
Length Conversion Factor
1 foot = 0.3048 metre
1 foot = 0.3048 metre (exact)
IEEE/ASTM SI 10
Volume Unit for Concrete/Earthwork
Cubic metre (m³)
Cubic metre (m³) is the standard SI unit for volume.
IEEE/ASTM SI 10
Unit of Force vs. Mass
Specifies mass units (kilogram, tonne) for quantities and loads. Does not explicitly mention the Newton.
Strictly distinguishes mass (kg) from force (Newton, N). Use of kilogram-force (kgf) is deprecated.
IEEE/ASTM SI 10
Modular Brick Size Concept
Recommends a modular size of 200 x 100 x 100 mm (including mortar) for bricks.
No single international size exists; varies by region. The concept is known as modular coordination (ISO 1006).
General Practice / ISO 1006
Unit for Reinforcement Steel
Quintal (100 kg) or tonne (1000 kg).
Kilogram (kg) or tonne (t). Quintal is not an SI unit and its use is discouraged.
IEEE/ASTM SI 10
⚠ Verify details from original standards before use
Key Values5
Quick Reference Values
1 Inch25.4 mm
1 Foot0.3048 m
1 Yard0.9144 m
1 Mile1.609 km
1 Square Foot0.0929 sq m
Tables & Referenced Sections
Key Tables
No tables data
Key Clauses
No clauses data
Frequently Asked Questions3
What is the main purpose of IS 965?+
It standardizes the equivalent metric units, dimensions, and drawing scales for construction works transitioning from or documented in imperial (FPS) units.
What is the recommended metric scale equivalent for 1/8 inch = 1 foot?+
1:100 is typically adopted as the closest practical metric equivalent for general layout plans.
Are imperial dimensions still permitted in standard Indian construction contracts?+
No, India officially adopted the metric system decades ago, and all modern BIS codes, CPWD specifications, and legal contracts strictly mandate SI (metric) units.