Lucky dimensions — Lu Ban ruler calculator
Chinese carpenters sized doors and furniture with the Lu Ban ruler, whose sections alternate between lucky and unlucky. Check any length in millimetres, centimetres or inches.
Result
Example — enter your own details and press Calculate.
Section 8 of 8: Ben 本 — Prosperity and a solid foundation.
The Lu Ban ruler
The ruler repeats every 43.2 cm and is divided into eight 5.4 cm sections: Cai (wealth), Bing (illness), Li (separation), Yi (helpful people), Guan (career), Jie (loss), Hai (harm) and Ben (prosperity). Four are auspicious and four inauspicious; the pattern continues for longer lengths.
Traditionally the rule is applied to door openings, windows, desks, beds and cabinets. For long pieces a small adjustment of a centimetre or two is usually enough to move into a lucky section.
Use it in your app
This calculator is the GET /api/v2/feng-shui/lucky-dimension endpoint of the Feng Shui API. Get a free key, then:
curl -H "X-API-Key: $FENGSHUI_API_KEY" \ "https://fengshui-api.com/api/v2/feng-shui/lucky-dimension?length=85&unit=cm"
Full reference in the API docs; ready-to-run programs in 8 languages on the code examples page.
Frequently asked questions
Is this calculator free?
Yes. The web calculator needs no account. For automated use, create a free account to get an API key.