Convert any date between the Gregorian (AD) calendar and the Nepali Bikram Sambat (BS / बिक्रम सम्बत) calendar, the official civil calendar of Nepal. The tool works in both directions and is accurate across the full supported range.
How it works
Bikram Sambat is a solar calendar whose month lengths range from 29 to 32 days and change from one year to the next. Because of this, a fixed year-offset would drift and cannot be used — the converter instead relies on the published per-year table of BS month lengths.
It anchors the two calendars at a known point — 1 Baisakh BS 2000 = 14 April 1943 — and uses the Julian Day Number (JDN) as a neutral day count:
- BS → AD: sum the days in all whole BS years, whole months and days before the target date, add to the anchor’s JDN, then convert that JDN to a Gregorian date.
- AD → BS: convert the Gregorian date to a JDN, subtract the anchor, then walk the table year by year and month by month, consuming days until the remainder lands on a BS date.
Supported range: BS 2000–2089 (≈ AD 1943–2033).
Example
Take 1 Baisakh 2080 BS. Walking the table from the anchor year 2000 up to 2080 and summing the month lengths, the converter lands on 14 April 2023 in the Gregorian calendar — confirming the roughly 56-to-57-year gap and the mid-April new year.
| BS month | Order | Typical length |
|---|---|---|
| Baisakh | 1 | 30–31 days |
| Ashadh | 3 | 31–32 days |
| Poush | 9 | 29–30 days |
| Chaitra | 12 | 30–31 days |
It is privacy-first: every calculation happens locally in your browser and nothing is ever sent anywhere.