Birthstone Calculator
Enter the birth month number (1–12) to get the corresponding birthstone.
Result
How it is calculated
This is a lookup, not a formula. You enter the birth month as a number from 1 (January) to 12 (December), and the tool returns the one stone assigned to that month in its list: January garnet, February amethyst, March aquamarine, April diamond, May emerald, June pearl, July ruby, August peridot, September sapphire, October opal, November topaz and December turquoise. A decimal is cut to a whole month (6.9 is read as 6), and numbers outside 1 to 12 give no result. Only the month matters, the day and year are not used. The tool shows a single stone per month. Some months also have traditional or alternative stones in other lists, and the choice varies by country and by jeweller.
Worked example
Someone is born in June and wants a birthstone gift. The month is entered as 6, the sixth month of the year. The tool looks up month 6 in its list and returns Pearl. The same lookup for month 12 would return Turquoise and for month 1 would return Garnet. Which day of June the birthday falls on makes no difference, because the stone depends on the month alone.
Common mistakes
- Typing the month name or the full date. The field expects the month number, so write 6 for June, not "June" or 15/06.
- Entering 0 or 13. Months run from 1 to 12, and anything outside that range gives no result.
- Assuming one global standard. This tool shows one stone per month; other countries and older lists name different or additional stones, so a jeweller may offer a different one.
- Mixing the birthstone with the zodiac stone. Zodiac signs change around the 20th of the month, while a birthstone follows the calendar month.
- Entering the month the gift is given in rather than the month the person was born.
About this calculator
This calculator looks up the modern birthstone for any birth month, using the standardized list adopted in 1912 by the American National Retail Jewelers Association (today's Jewelers of America). The list runs from garnet in January through amethyst in February, aquamarine in March, and on to topaz in November and turquoise in December.
The calculator returns one classic stone per month; some months have additional accepted alternatives in newer lists, which it does not show. Jewellers, gift-buyers and anyone shopping for a birthday or push present use this list as the go-to reference for a personally meaningful stone.
Was this helpful?
You can pick up to 3 reactions.
Popular calculators
Loan Calculator
Monthly payment, total interest and full amortization schedule.
Percentage Calculator
Percent change, percent of, and ratio calculations.
Discount Calculator
Calculate final price, savings, and discount amount.
BMI Calculator
Body mass index from height and weight (metric or imperial).
Age Calculator
Compute your exact age in years, months and days from a birth date.
Compound Interest Calculator
Calculate the final amount and interest earned with compounding.
All Calculators
- Loan Calculator
- Profit Calculator
- Discount Calculator
- BMI Calculator
- Percentage Calculator
- Ideal Weight Calculator
- Age Calculator
- Pregnancy Due Date Calculator
- Compound Interest Calculator
- BMR Calculator (Basal Metabolic Rate)
- Tip Calculator
- Fuel Cost Calculator
- Date Difference Calculator
- Sleep Cycle Calculator
- Daily Water Intake Calculator
- Simple Interest Calculator
- Heart Rate Zones Calculator
- Running Pace Calculator
- Pet Age Calculator
- Calories Burned Calculator
- Macro Calculator
- TDEE Calculator (Total Daily Energy Expenditure)
- Waist-to-Hip Ratio Calculator
- Honor Roll Calculator
- One Rep Max (1RM) Calculator
- Ovulation Calculator
- Electricity Cost Calculator
- Unit Price Calculator
- Savings Goal Calculator
- Break-Even Point Calculator
- Paint Calculator
- Course Grade Average Calculator
- Business Days Calculator
- Time Duration Calculator
- Fuel Economy Calculator
- Temperature Converter
- Tile Calculator
- Aspect Ratio Calculator
- Roman Numeral Converter
- Goal Weight Timeline Calculator
- Salary Converter (Hourly to Annual)
- Credit Card Validator (Luhn)
- Body Surface Area (BSA) Calculator
- Feels-Like Temperature Calculator
- Ohm’s Law Calculator
- PPI (Pixel Density) Calculator
- Molar Mass Calculator
- Zodiac Sign Calculator (Western + Chinese)
- IBAN Validator
- Shoe Size Converter
- Country Info & Dialing Code Lookup
- Time Zone Difference (World Clock)
- CAGR (Compound Annual Growth Rate) Calculator
- Rule of 72 Calculator
- Blood Alcohol Content (BAC) Calculator
- Lean Body Mass (LBM) Calculator
- Pythagorean Theorem Calculator
- Speed Converter
- Download Time Calculator
- Date Calculator (Add/Subtract)
No calculators found
Comments (1)
This is the 1912 American list with a single stone per month, so treat it as a starting point for a gift rather than a rule. Some months, June for one, also carry extra stones on newer lists, and jewellers abroad may offer different ones. If you are choosing between stones, ask the jeweller which list they follow. Does your country or family tradition use a different stone for any month?