How this calculator works
- Step 1Weight1 tola180 grains.
- Step 2Grams11.663804 g180 × 64.79891 mg.
- Step 3Purity22K = 916Parts of gold per thousand, BIS minimum.
- Step 4Pure gold10.684044 gGrams × 916 ÷ 1000.
Every unit is converted through the grain, which is defined as exactly 64.79891 milligrams. A tola is 180 grains and a troy ounce is 480 grains, so both have exact gram values.
The purity grade then gives the minimum share of pure gold. The rest is alloy, such as copper or silver, added for strength.
Worked example: one tola of 22K
- Grams
tolas × 180 × 0.06479891- Pure gold
grams × fineness ÷ 1000
- wWeight 1 tola
- fFineness of 22K 916
- Grains1 × 180180
- Grams180 × 0.0647989111.663804
- Pure gold11.663804 × 916 ÷ 100010.684044 g
Ten grams, the unit Indian gold rates are usually quoted in, is 0.857353 tola.
Pure gold by grade
The number after the grade is the fineness: parts of gold per thousand. 22K is 916, not 22 ÷ 24 = 916.67, because BIS sets whole-number minimums.
Tola, gram or troy ounce
- 1 tola11.663804 gTraditional unit, 180 grains.
- 10 grams0.857353 tolaUnit for most Indian gold rates.
- 1 troy ounce31.103477 gUnit for international prices, 480 grains.
Read the result
The headline is the weight in grams; the table gives every unit plus the minimum pure gold and alloy.
The pure gold figure is the minimum the hallmark grade guarantees. Actual purity can be slightly higher.
Assumptions and limits
- Standard tola180 grains; some jewellers use a rounded 10-gram tola.
- BIS minimumsFineness values from IS 1417:2016 hallmark grades.
- No pricesRates, making charges and GST are not included.
- Stones excludedEnter the gold weight only, not stones or enamel.
Related conversion tools
Gold is weighed in grams, tola or troy ounces. Purity sets how much of that is gold.
For other weight and volume units, use the unit converter. To compare prices per gram, the unit price calculator shows which offer is cheaper.
Common mistakes
Mistake: Treating 22K as 91.67% gold.
Instead: Use the BIS minimum of 916 parts per thousand.
Mistake: Assuming every tola is 10 grams.
Instead: Ask which tola a quote uses; the standard one is about 11.66 g.
Mistake: Including stone weight in gold weight.
Instead: Use the net gold weight shown on the bill.
Checking the method
Every golden case is recomputed in exact grains with Python fractions.
An independent script turns each weight into exact grains before converting, and checks every figure. Unit definitions come from NIST and the Standards of Weight Act, 1939; grades from BIS.
Read how we test our calculators, or browse more everyday tools.