Inputs

Room length m Enter a numeric project value in m at or above 0.1. Room width m Enter a numeric project value in m at or above 0.1. Mounting height above target plane m Enter a numeric project value in m at or above 0.01. Beam angle deg Enter a numeric project value in deg between 0.1 and 179. Target beam overlap ratio Enter a numeric project value in ratio between 0 and 0.99. Wall offset assumption m Enter a numeric project value in m at or above 0.

Beam diameter -- m

Recommended spacing -- m

Edge distance -- m

Beam coverage area -- m2

Calculation details

Beam diameter: -- m
Recommended spacing: -- m
Edge distance: -- m
Beam coverage area: -- m2

Important notes

Use the manufacturer beam-angle definition where available.
Australian lighting standards may inform the planning boundary; this calculator does not make an automatic compliance determination.

Formulas

\(\displaystyle D = 2H\tan(\theta/2)\)
\(\displaystyle S = D(1-O)\)
This is a geometry planning estimate; photometric review and site-specific requirements remain separate.

Estimate downlight spacing from beam geometry, overlap, and a wall offset assumption.

Downlight Spacing Calculator is a planning aid. Keep the target source, product data, measurement method, and project assumptions with the result. Confirm compliance, installation, certification, and safety decisions with the responsible professional.

Inputs

Results

Formulas