What Is Ratti? Ratti to Carat Conversion and How Much Weight to Wear
Every astrologer's recommendation comes with a number: "wear a 5 ratti Yellow Sapphire" or "a 6 ratti Red Coral." But jewellers and laboratory reports speak in carats. This guide, from the House of Shubh Gems, India's most trusted name for natural gemstones for over 25 years, explains what ratti means, how to convert it to carats and how to choose the right weight.
What Is Ratti?
Ratti is a traditional Indian unit of weight, originally based on the seed of the gunja plant (Abrus precatorius), a small scarlet seed with a black spot. It has been used for centuries to weigh gemstones and is still the unit most astrologers use for remedial gemstones.
Ratti to Carat Conversion
The carat is the international unit of gemstone weight, fixed at exactly 200 milligrams since 1907. For astrological gemstones, the standard conversion is:
1 ratti = 0.91 carat (182 mg)
To convert ratti to carats, multiply by 0.91. To convert carats to ratti, divide by 0.91.
- 3 ratti = 2.73 carats
- 4 ratti = 3.64 carats
- 5 ratti = 4.55 carats
- 6 ratti = 5.46 carats
- 7 ratti = 6.37 carats
- 8 ratti = 7.28 carats
- 9 ratti = 8.19 carats
For example, a gemstone weighing 4.55 carats is 4.55 ÷ 0.91 = 5 ratti.
Why Ratti and Carat Get Confused
Ratti was never a perfectly fixed unit. Jewellers traditionally used a smaller "sunari" ratti of about 121 mg, while the astrological ratti is 182 mg. Values also varied from region to region. Some sellers and websites even treat 1 ratti as equal to 1 carat, which can leave a buyer with a gemstone lighter than intended.
The safest approach is to always ask for the weight in carats, and check it against the laboratory report, which records weight in carats. Convert to ratti yourself using the formula above.
How Much Ratti Should You Wear?
There is no single answer. No classical text gives a fixed rule, and astrologers use different methods. The most common guideline is based on body weight:
Body weight in kg ÷ 12 = ratti
- A 60 kg person: 60 ÷ 12 = 5 ratti (4.55 carats)
- An 84 kg person: 84 ÷ 12 = 7 ratti (6.37 carats)
Treat this as a starting point, not a rule. Your astrologer may adjust the weight based on:
- Your chart: the strength of the planet and your current dasha
- The gemstone: some are traditionally worn heavier, others lighter
- The finger and setting: a little-finger ring suits a smaller gemstone
- Your budget
More weight does not automatically mean more benefit, so wearing a much heavier gemstone than advised adds nothing.
Quality Matters More Than Weight
A clean, well-cut, natural gemstone of the right weight is better than a heavier one with flaws. Check colour, clarity and cut along with weight. Different gemstones have different densities, so two gemstones of equal weight can look different in size.
Weight also means little if the gemstone is not what it claims to be. Insist on a report from an independent, trusted laboratory such as IGI, IIGJ or GIA, confirming the gemstone is natural, unheated and untreated. Every gemstone at Only Natural Gemstones is 100% natural, unheated and untreated, and comes with this certification and its weight in carats.
How to Check the Weight of Your Gemstone
- Read the carat weight on the laboratory report.
- Convert to ratti by dividing by 0.91.
- Compare with your astrologer's advice and confirm it matches.
- Check the measurements on the report against your gemstone.
Frequently Asked Questions
How many carats is 1 ratti?
1 ratti = 0.91 carat.
How do I convert carats to ratti?
Divide the carat weight by 0.91. For example, 4.55 carats ÷ 0.91 = 5 ratti.
Is 1 ratti the same as 1 carat?
No. 1 ratti is 0.91 carat, so a gemstone weighing 5 ratti is 4.55 carats, not 5.
How many ratti should I wear?
A common guideline is your body weight in kg divided by 12, but your astrologer's advice based on your chart should decide.
Does a heavier gemstone work better?
Not necessarily. A natural, well-cut gemstone of the advised weight is what matters.
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