LUBAN RULER — SCROLL TO ANY SIZE, READ GOOD & BAD ZONES INSTANTLY

The Luban ruler (魯班尺) is the traditional Feng Shui measuring tool used to pick auspicious dimensions — and avoid inauspicious ones — for doors, furniture, altars and home construction. This app brings all 3 standard Luban rulers to your phone: drag the ruler or type a measurement, and all three rulers read out results side by side.

— 3 STANDARD RULERS, SIDE BY SIDE —

• CLEAR OPENING 52.2cm (8 sections) — for main doors, windows, room doors, gates
• YANG DWELLING 42.9cm (8 sections) — for kitchens, stairs, beds, cabinets, furniture
• YIN DWELLING / DING LAN 38.8cm (10 sections) — for altars, ancestral tablets, tombs

Every section and sub-section comes with its full name and meaning in plain English.

— KEY FEATURES —

• Buttery-smooth, endless scrolling; tap the number box to type a size (mm or inch)
• Instant Good/Bad verdict with section names and meanings for all 3 rulers at once
• NEAREST LUCKY SIZE SUGGESTION: land on a bad zone and the app tells you exactly how many mm to add or remove to reach the nearest good zone
• ±1mm fine-tune buttons and quick reset to zero
• Haptic ticks while scrolling, warning buzz when entering a bad zone (can be turned off)
• Light & Dark themes, one-tap switch
• 3 languages: English, Tiếng Việt, 中文 — switch inside the app
• Detailed built-in guide explaining every section
• Works 100% OFFLINE — no ads, no data collection

— HOW TO USE —

1. Drag the ruler (or type a measurement) to the size you want to check
2. Read the red center line: each ruler shows its zone at that position
3. Rule of thumb: "Use the red zones, avoid the black zones"

NOTE: the on-screen ruler is for looking up Feng Shui zones by measurement (use a real tape measure on physical objects). Feng Shui content is provided for cultural reference.

Developed by Manh Nguyen — manh.work
Feedback: manhdotme@gmail.com