Lighting Layout Calculator
Enter room dimensions, mounting height, spacing criterion, and fixture lumens for a first-pass layout estimate.
- Room area
- sq ft
- Spacing limit
- ft
- Recommended columns
- Recommended rows
- Recommended fixture count
- Average lux estimate
- lux
Calculation details
- Calculation basis
- Lighting boundary
Recent results
Formulas
- Room area = room length x room width
- Spacing limit = mounting height x spacing criterion
- Columns = ceiling(room length / spacing limit)
- Rows = ceiling(room width / spacing limit)
- Fixture count = columns x rows
- Average lux estimate = fixture count x fixture lumens / room area in square meters
Use this calculator
Estimate fixture rows, columns, spacing, and average illuminance from room dimensions and a spacing criterion.
Read the result
Review the calculated values with their displayed units and assumptions. The result is a planning aid for the stated inputs, not a final equipment or installation decision.
Check before final work
This lighting layout estimate uses idealized room geometry and entered lumens. It does not model photometric distribution, coefficient of utilization, light-loss factor, glare, obstructions, controls, emergency lighting, or energy-code compliance.
FAQs
Does this replace a photometric layout?
No. It is a first-pass spacing and count estimate. Final lighting design needs fixture photometry, mounting conditions, light-loss assumptions, controls, obstructions, and project criteria.
Why can the average lux estimate differ from the target?
This page uses nominal fixture lumens divided by converted room area and does not apply utilization or light-loss factors.