💎 Momme Weight Converter (匁 to g)

The Momme Weight Converter converts between momme (匁, sometimes written as "monme") and modern weight units. The momme equals 3.75 g and is the fundamental unit of the traditional Japanese weight system.

The momme is the international standard for pearl weight. Akoya, South Sea, and Tahitian pearl prices are quoted per momme. A typical 7.5 mm Akoya pearl strand weighs about 25 momme (93.75 g). The momme is also used in Japanese gold retail.

Conversion formula:

Key relationships:

• 1 momme = 3.75 g
• 1 momme = 18.75 carat (1 carat = 0.2 g)
• 1 momme = 0.1323 troy ounces
• 1000 momme = 1 kan = 3.75 kg

Pearl weight guide:

• Single 7.5 mm Akoya pearl: ~0.5 momme (1.875 g)
• 50-piece 7.5 mm strand: ~25 momme (93.75 g)
• Single 10 mm South Sea pearl: ~2 momme (7.5 g)

For bulk weights (tuna, large quantities), see our kan (3.75 kg) converter. For general weight conversions, the weight converter handles all metric units. The shakkanho bundle converter covers all traditional Japanese units.

1. Enter the weight in momme (e.g. 25 for a pearl strand).
2. Select the target unit (grams, carats, ounces, etc.).
3. Click Convert to see the result.
4. Use the pearl weight guide for reference.

How many grams is one momme?

One momme equals exactly 3.75 g. This was standardized during the Meiji era and is used internationally in the pearl trade. The momme is the base unit of the traditional Japanese weight system.

How many carats is one momme?

One momme equals 18.75 carat (since 1 carat = 0.2 g and 1 momme = 3.75 g). When comparing pearl prices, always check whether the price is per momme or per carat - they differ significantly.

Why are pearls measured in momme?

Japan dominated Akoya pearl cultivation in the early 20th century and established momme as the standard weight unit. The practice spread globally and remains the convention for all pearl types: Akoya, South Sea, and Tahitian.

How much does a typical pearl strand weigh?

A standard 7.5 mm Akoya pearl strand (50 pearls) weighs approximately 25 momme (93.75 g). Larger South Sea strands can weigh 50+ momme. Each individual 7.5 mm Akoya pearl weighs about 0.5 momme (1.875 g).

Is momme still used in Japan?

Yes. The momme is used in pearl trading (internationally), Japanese gold and silver retail, and some traditional pharmacies. It was abolished for general commerce in 1958 but persists in these specialized industries.

Momme vs carat for pearls. Pearls are weighed in momme (not carat) by international convention. 1 momme = 18.75 carat. A 25-momme strand equals 468.75 carat. Always clarify the unit when comparing prices.

Gold trading in momme. Some Japanese gold retailers quote prices per momme (3.75 g) alongside per-gram pricing. The momme price is typically exactly 3.75 times the per-gram price.

Etymology: The word "momme" comes from the Japanese 匁, which historically referred to a small copper coin. The unit was standardized at 3.75 g during the Meiji era and adopted internationally for pearl trading.

Pearl valuation: Larger, rounder pearls with better luster cost more per momme. A premium Akoya strand might cost 50,000 yen per momme, while a standard strand costs 3,000-5,000 yen per momme.