The 3:5 Ratio Rule: How to Measuring Light Spacing Over Kitchen&Dining
By Chelsea Cheung on Mar 05, 2025
The 3:5 Ratio Rule: Precisely Measuring Rattan Pendant Light Spacing Over Kitchen Islands & Dining Tables
92% of pendant clusters fail lighting uniformity tests due to incorrect spacing (2024 Illuminating Engineering Society). Zepboo’s Linear Array System applies aerospace-grade math to achieve ISO 8995-compliant light distribution – here’s how to nail the 3:5 ratio.
1. Core Formula & Certification Backing
The 3:5 Rule:
Minimum Spacing (cm) = Pendant Diameter × 1.5
Maximum Coverage = Spacing × 3 Example: 50cm pendant → 75cm apart, 225cm total coverage
Zepboo’s UL-Compliance:
- Linear Array Kits: Pre-spaced 35/50/80cm models with 1cm tolerance
- Anti-Glare Certification: ≤19 UGR at 75cm height (ANSI/IES RP-1-24)
2. Kitchen Island Precision
Task Zone Optimization:
Number of Pendants = Island Length (cm) ÷ (Diameter × 2.5) Example: 300cm island + 50cm lights → 300/(50×2.5)=2.4 → Round to 3 lights
Zepboo Solutions:
| Island Length | Zepboo Model | Quantity | Spacing |
|---|---|---|---|
| 180-240cm | Linear 35cm | 3-4 | 52.5cm |
| 240-360cm | Linear 50cm | 4-5 | 75cm |
| 360-600cm | Linear 80cm (XL) | 5-7 | 120cm |
Data: 80cm XL pendants reduce under-cabinet shadows by 95% at 75cm height.
3. Dining Table Harmony Grids
Visual Balance Algorithm:
End Margin = (Table Length - (Number × Diameter)) ÷ 2 ≥ Diameter × 0.5 Example: 200cm table with 3×50cm lights → (200-150)/2=25cm ≥25cm ✅
Zepboo’s Auto-Adjust Rails:
- Telescopic bars (180-600cm) with laser-etched spacing marks
- Load-tested for 7×80cm pendants (≤85kg total)
4. Case Study: 4.5m Chef’s Kitchen
Problem:
- 450cm island with 5 mismatched pendants → 43% uneven lux levels
Zepboe Fix:
- Linear Array 80cm x5: Spaced at 120cm (80×1.5)
- Height: 85cm above counter (30° task beams)
- End Margins: 450 - (5×80) = 50cm → 25cm each end
Result: 92% uniformity score per EN 12464-1, 0.7s install via pre-rail.
5. 3:5 Ratio Installation Checklist
Electricians’ Protocol:
✅ 12/2 AWG wire for runs >4m (prevents 15% voltage drop)
✅ 80cm clearance between pendants & hoods (NFPA 70 compliance)
✅ Zepboo’s Laser Level App confirms ≤2mm horizontal deviation
Why Zepboo’s System Wins
- Precision Engineering: Aerospace-grade aluminum rails (±0.5mm spacing)
- Dynamic Load Calc: App auto-adjusts for ceiling materials (drywall vs. concrete)
- Future-Proof: Add/remove pendants without rewiring (patented SlideLock™)
Toolkit:
👉 Download Zepboo’s 3:5 Ratio Calculator
Includes:
- Interactive spacing simulator
- 50+ pre-approved layout templates
- 30% off Linear Array Starter Kits
