Pick a date in either calendar and press Convert.
This tool converts a date between Bikram Sambat (BS), Nepal's official calendar, and the Gregorian calendar (AD). Pick a date in either calendar and it shows the matching date in the other, with the weekday. It covers about BS 2000 to BS 2100 (AD 1943 to 2044). Birth certificates, citizenship cards and other official documents in use today fall inside this range.
Bikram Sambat is a solar calendar. Each month starts when the sun enters a new sidereal sign, so a month can have 29 to 32 days. The same month also changes length from year to year. For example, Baisakh can have 31 days one year and 30 the next. Because of this, a fixed rule such as "add 56 years and 8 months" gives wrong dates. Correct conversion needs the month-length table for each BS year. This converter uses those per-year tables, the same data printed Nepali patros use.
The Bikram Sambat era is 56 years and about 8½ months ahead of the Gregorian era, so BS 2082 covers parts of AD 2025 and 2026. The BS new year (Baisakh 1) falls in mid-April. From January to mid-April the difference is 56 years. From mid-April to December it is 57 years. Example: a birth date of 15 Poush 2046. Poush falls in December, after the new year, so subtract 57: the AD year is 1989. Using the wrong number here is the most common mistake in manual conversion, mostly for birthdays close to the new year.
Common uses: converting a BS birth date to AD for a passport, visa form, foreign university application or other international document; converting an AD date to BS for Nepali government paperwork, land registration or citizenship records; and finding the weekday of an old date. The converter also shows the tithi and calendar events for the selected day.
The Age and Difference tools, linked from the tabs above, use the same conversion tables. The Age tool gives your exact age from a BS or AD date of birth. It also shows your age on a form's cut-off date and the BS dates when you turn 16, 18 and 20. The Difference tool counts the days between two dates in either calendar, and adds or subtracts days from a Nepali date.
The converter uses the official month-length data for each Bikram Sambat year. Results are checked against the tables used in printed Nepali patros. For years far in the future, month lengths come from astronomical calculation and can change slightly when a new official patro is published. Dates within a year or two of today are exact.
In the BS Date → AD Date box, pick your birth year, month and day, and press Convert. Use the AD result on passport and visa forms. Check the year: a birth from Baisakh 1 (mid-April) to mid-Poush (31 December) is 57 years less than the BS year. A birth from mid-Poush (1 January) to the end of Chaitra is 56 years less.
Today is 30 Ashwin 2083 (16 Oct 2026). The homepage calendar shows the full current BS month with the tithi and events for each day.
Some sites use a fixed offset instead of the real month table for each year. Their results can be off by one or two days, mostly near the start or end of a month. This converter uses the month-length table for each BS year, so it matches the official printed patro.
Between 29 and 32 days, and the same month can have a different length in different years. You need that year's table to know, for example, how many days Bhadra has. That is why conversion is done with tables.
Subtracting gives only the year. BS months start in the middle of AD months and their lengths change every year, so the month and day do not match by a fixed offset. Even with the right year, the date can be a few days off. The converter uses the month table for the BS year you pick.
Excel has no Bikram Sambat calendar. Formulas that add a fixed number of days go wrong near month ends. For a few dates, convert them here. For a large sheet, build a lookup table from the official month lengths. The BS month-lengths page lists them for this year and next year.
About BS 2000 to 2100, which is AD 1943 to 2044. Most document dates fall in this range. If you need a date outside it, contact us through the feedback page.
