Weights and Measures of the Indus Valley Civilization

1.1 What were weights and measures in the Indus civilisation?

The Harappans used a standard set of stone weights and a few marked rulers. Weights came in fixed steps, so a trader could weigh goods the same way in different towns.

The mature phase of the civilisation ran from about 2600 to 1900 BCE. That is roughly 4,000 to 4,600 years ago.

1.2 Why does this matter for exams?

Standard weights are evidence of organised trade and exact measuring. UPSC used this idea in the Prelims 2026 paper. The details are in card 6.

2.1 What were the weights made of?

Most weights are neat cubes of banded grey chert. The stone came mainly from the Rohri hills in Sindh.

A few weights use slate, alabaster, quartzite or jasper. Some are truncated spheres of agate or chalcedony. Their two flat faces stopped them from rolling away.

2.2 How were the weights graded?

The small weights doubled at each step. This is a binary system. The large weights followed a decimal system instead.

Note that 12,800 belongs to the decimal range, not the binary run.

2.3 How heavy were they?

The base unit works out at about 0.86 grams. The most common weight is the 16th ratio. It weighs about 13.7 grams. The heaviest weight found at Mohenjo-daro is 10,865 grams, or about 25 pounds.

3.1 Where did the weight system come from?

No one knows for sure. One idea links the base unit to the gunja seed. This is the seed of the Abrus plant. About eight seeds weigh roughly one base unit. Kenoyer notes that other seeds could also have set the unit.

3.2 How were the weights used?

NCERT says the weights regulated exchange and were usually without markings. The smaller ones probably weighed jewellery and beads. Metal scale-pans have also been found.

Kenoyer finds the most weights near city gateways and craft areas. Goods entering a city may have been weighed and taxed there. Bead makers also helped make the weights.

3.3 Was the system sudden?

No. Kenoyer argues it spread slowly over 200 to 250 years, between 2600 and 2450 BCE. The stone cubes vanished with the civilisation. The system of weights lived on into the Early Historical period. Kenoyer says it is still used across South Asia.

4.1 What is the Mohenjo-daro shell scale?

It is a ruler made of shell, found broken at both ends. Ernest Mackay, who directed the excavation, called it a measure of length. Its divisions are about 1.32 inches, or 3.35 cm.

The rod is divided on a decimal plan. Groups of ten divisions are marked by circles. Ten units probably give about 13.2 inches, close to the foot used across western Asia.

4.2 What other lengths were in use?

• A cubit of about 20.7 inches, or 52.6 cm, is also reported. Kenoyer gives 52.83 cm. Use “about 52 to 53 cm”.
• A bronze rod from Harappa is marked in lengths of about 0.367 inch, or 0.93 cm. Britannica reads this as half a digit of the cubit.
• The Kalibangan scale is reported to have a unit of 17.5 cm. That figure comes from a secondary source.

4.3 How accurate were these scales?

Petrie measured a cast of the Mohenjo-daro scale. He found a mean error of graduation of 0.003 inch. That is very small. Britannica adds that measurements from some structures show the units were applied in practice.

4.4 Were bricks measured too?

Yes. NCERT says Harappan bricks were in the ratio 4:2:1 for length, breadth and height. The ratio held from Jammu to Gujarat. Kenoyer links it to the width of a hand.

5.1 What does the standardisation show?

It shows careful trade and craft work. Kenoyer cautions that this standard does not point to one overarching authoritarian or political force.

Cities followed a general common standard, with some regional variation. So “identical everywhere” is too strong.

5.2 How does this link to trade abroad?

Harappan seals have been found at Ur. NCERT lists seals and weights among finds that suggest long-distance contact. Mesopotamian texts name Meluhha, which may be the Harappan region. Trade with Meluhha is recorded from about 2350 BCE.

5.3 What about Lothal?

Lothal in Gujarat was excavated between 1955 and 1962. The excavator announced a dockyard there, and Ratnagar says the claim caused a stir. The large basin is an interpretation.

5.4 Is the weight scheme settled?

No. A later analysis that added Lothal weights proposes two decimal series. Britannica says much work remains to understand the full system.

6.1 How did UPSC use this?

6.2 Which facts do students mix up?

• Binary ends at 64. Decimal runs from 160 to 12,800.
• 13.2 inches is the foot. The cubit is about 20.7 inches.
• Base unit about 0.86 g. Most common weight about 13.7 g.
• Mohenjo-daro had the shell scale. Harappa had the bronze rod.
• Lothal’s dock is an interpretation, not a settled fact.