Written by Sameer
Reviewed on
So what is a ratti?
The ratti is the old South Asian unit for weighing small, precious things. It is named after the seed of the ratti plant, which jewellers once used as a counterweight on their scales. Gem dealers across Pakistan still talk in ratti, and many buyers picture a stone as "a 5 ratti neelam" rather than thinking in carats.
The carat is the international unit. One carat is exactly 0.2 grams, and every certificate and lab report states weight in carats. The converter above connects the two systems.
Standard ratti versus sunari ratti
Two different units share the name ratti, and confusing them is the single biggest source of misunderstanding in the bazaar.
- Standard ratti (gem ratti): 0.91 carat, roughly 0.182 g. This is the ratti used for gemstones in Pakistan, and whenever Authentic Gems says ratti, this is the one we mean.
- Sunari ratti (goldsmith's ratti): about 0.1215 g, or roughly 0.61 carat. It comes from the tola-masha-ratti system used for gold: 8 ratti make a masha and 12 masha make a tola, so one tola is 96 sunari ratti, about 11.66 g.
A sunari ratti is around a third lighter than a standard one. If a goldsmith working in sunari ratti calls a stone "9 ratti", it weighs about 1.09 g, which is only about 6 standard ratti. Before you compare two quotes, ask each seller which ratti they are using. Some sellers use other local values, so if a weight looks strange, ask for it in carats.
Why jewellers here still quote in ratti
Ratti is the unit most of us grew up hearing. Gold has been weighed in tola, masha and ratti for generations, and gemstones simply followed suit. Astrologers who recommend a pukhraj or neelam often state the weight in ratti as well, so customers come asking for a stone "of at least 5 ratti" or "between 7 and 8 ratti". The trade also prices many stones per ratti, which is why it pays to understand how a per-ratti rate lines up against a per-carat one.
Doing the sums yourself
You only need three numbers: 1 standard ratti = 0.91 carat, 1 standard ratti = 0.182 g, and 1 carat = 0.2 g.
- Ratti to carats: multiply by 0.91.
- Carats to ratti: divide by 0.91.
- Ratti to grams: multiply by 0.182.
- Carats to grams: multiply by 0.2.
- Grams to ratti: divide by 0.182.
Examples worked through
- 6 ratti into carats and grams. 6 x 0.91 = 5.46 carats. 5.46 x 0.2 = 1.092 g, which matches 6 x 0.182.
- A certificate reads 3.64 carats. 3.64 / 0.91 = 4, so the stone is exactly 4 ratti.
- An awkward weight: 2.75 carats. 2.75 / 0.91 = 3.02 ratti. Most sellers would describe it as "just over 3 ratti".
- Grams to ratti: 1.5 g. 1.5 / 0.182 = 8.24 ratti. To double-check, 1.5 / 0.2 = 7.5 carats, and 7.5 / 0.91 = 8.24 ratti.
- Sunari ratti into standard ratti: 9 sunari ratti. 9 x 0.1215 = 1.0935 g, which is 5.47 carats (1.0935 / 0.2). Divide that by 0.91 and you have about 6.01 standard ratti.
Leave the rounding until the very end. Rounding 0.91 down to 0.9 looks harmless, but on a 10 ratti stone it moves the answer by a tenth of a carat.
Per-ratti and per-carat rates
Since a standard ratti is 0.91 carat, the same number links the two rates:
- Per-ratti rate = per-carat rate x 0.91.
- Per-carat rate = per-ratti rate / 0.91.
For any given stone, the per-ratti figure is always a little lower than the per-carat figure, simply because a ratti is a little less than a carat. The total does not change: a 4.55 carat stone is 5 ratti, so its per-carat rate times 4.55 and its per-ratti rate times 5 come to the same amount. If two quotes for similar stones still disagree after converting, check the unit first. A per-ratti rate worked out in sunari ratti comes to about 0.61 of the per-carat rate instead of 0.91, which can make a stone look cheaper than it really is.
Weight is just one piece of value. Colour, clarity, cut, origin and treatment move the price much more than a fraction of a ratti. Our gemstone prices in Pakistan guide shows per-carat and per-ratti levels across our own listings, updated monthly, and every stone in the blue sapphire, yellow sapphire and ruby categories lists its carat weight and its own price. If a weight on a certificate puzzles you, our guide to reading a lab certificate goes through it line by line.
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