Calculator inputs
Example data table
| Zone | Ceiling | Surface | Clearance | Fixture height | Drop to bottom | Chain/cord |
|---|---|---|---|---|---|---|
| Table/Cart | 8 ft | 30 in | 33 in | 12 in | 33 in | 20 in |
| Plant Bench | 9 ft | 36 in | 27 in | 10 in | 45 in | 34 in |
| Walkway/Entry | 8 ft 6 in | Floor | 90 in | 8 in | 12 in | 3 in* |
Formula used
All calculations are performed in inches internally, then converted if needed.
- BottomHeight = SurfaceHeight + Clearance (walkway uses floor as surface)
- DropToBottom = CeilingHeight − BottomHeight
- CordLength = DropToBottom − FixtureHeight − CanopyDrop
- ShownCord = clamp(CordLength, MinChain, MaxChain)
How to use this calculator
- Pick your zone: table/cart, plant bench, or walkway.
- Enter ceiling height, then surface height if needed.
- Set a clearance target, or leave it blank.
- Add fixture height to estimate chain/cord length.
- Adjust chain limits to match your hardware.
- Press calculate, then export CSV or PDF.
Why pendant height matters in garden environments
Outdoor dining nooks, pergolas, and garden rooms mix humidity, wind, and reflective glazing that can amplify glare. A pendant hung too low blocks sightlines and invites bumps; too high and the work surface is dim. This calculator standardizes planning by connecting ceiling height, the working surface, and a practical safety gap so you can repeat the same method across spaces. It also flags when semi‑flush options fit better.
Recommended clearances by common zone
Clearance targets differ by use. Over tables or carts, 30–36 inches above the surface usually keeps faces visible and reduces glare. Over plant benches, 24–30 inches supports detailed tasks like potting and pruning. For walkways, plan the bottom about 84–96 inches above finished floor to protect head clearance. Leaving clearance blank applies a midpoint and still shows a full range.
How fixture size changes the drop calculation
Fixture height changes the needed cord or chain length. The tool subtracts fixture height and canopy drop from the ceiling‑to‑bottom drop so your order reflects real hardware. Tall shades, deep cages, and integrated housings can reduce cord length quickly. Enter measured dimensions from the spec sheet, including any stem collar, to avoid arriving short on site.
Planning multiple pendants and spacing
Multiple pendants benefit from deliberate spacing. A common starting point is 24–30 inches center‑to‑center, then adjust for fixture diameter and the zone’s width. The calculator estimates total span as spacing multiplied by pendant count minus one. Use the span to confirm your layout fits between beams, within a pergola bay, or centered over a bench run before drilling mounts.
Exporting results for installers and purchasing
After submission, results appear above the form for quick review. Export to CSV for estimating and to PDF for job folders or installer handoff. Exports include inputs, bottom‑height targets, recommended ranges, and the cord length clamped to your chosen min and max limits. This reduces back‑and‑forth, supports consistent heights across adjacent zones, and limits rework during installation.
FAQs
What if I do not know the best clearance?
Leave clearance blank. The calculator selects a midpoint for your zone and still shows minimum and maximum ranges for comparison.
Why does walkway mode not ask for surface height?
Walkway mode uses the finished floor as the reference. Your target becomes bottom height above floor, focused on safe head clearance.
Why is my chain or cord length clamped?
Clamping keeps the displayed length within your min and max hardware limits. If the raw value is outside, adjust clearance, fixture height, or mounting approach.
Should I enter fixture height when using a downrod?
Yes. Include the body height plus any collar or coupling so the final bottom position is accurate and ordering is not short.
How do I handle a sloped pergola or vaulted ceiling?
Measure the ceiling height at each mounting point. For multiple pendants along a slope, calculate each location separately to keep consistent bottom heights.
Do these numbers replace local electrical guidance?
No. This is a planning tool. Always follow local codes, fixture ratings for damp locations, and qualified installation practices.