The rings of a luo pan
A traditional luo pan can have dozens of rings; a practitioner's working set is much smaller. This online version shows the three that almost every feng shui method relies on:
- The degree ring — 360°, with labels every 30°.
- The 24 mountains (二十四山) — 24 sectors of 15° each, named after the twelve earthly branches, eight of the heavenly stems and four trigrams. Flying Star charts and facing directions are read on this ring.
- The eight trigrams in the Later Heaven arrangement, with the direction letters, which is what Eight Mansions and the compass bagua use.
The red shaded sector you'll see in other tools on this site marks a house's facing mountain; the green one marks the sitting mountain.
Floor plan or map?
On a floor plan, you set north yourself, using the north arrow on the drawing or a direction you've already measured. Place the dial at the centre of the home and click a door, window or room to read its direction from the centre.
On a map, the dial is centred on the middle of the screen and turned automatically to magnetic north for that location, using the World Magnetic Model. Pan the map so your house sits under the centre of the dial. To measure the facing of the house itself, the facing finder is quicker.
Magnetic north, true north and the luo pan
A physical luo pan has a magnetic needle, so it reads directions relative to magnetic north. Maps are drawn to true north. The two differ by the magnetic declination — more than 10° in much of the United States and Canada. In map mode this tool rotates the dial by the local declination, so the directions you read are what a luo pan would show on site.
Questions
Why are the mountain names in Chinese?
They are the traditional names. Each sector also shows its pinyin name, and the readout gives its code (for example S2 for Wu, the middle of South).
Can I use this instead of a real luo pan?
For working out directions from a plan or map, yes. On site, a physical compass or the phone compass is handy — keep it away from steel, cars and appliances, which pull the needle.