Bedside Reading Beam Calculator Australia

Calculate bedside reading beam diameter, coverage area and target-area ratio from mounting height and beam angle.

Reading beam

Mounting height, reading plane and beam angle

Enter the bedside fitting height, book or reading plane height, beam angle and target area. The result checks the geometric reading patch before glare and controls are judged.

Height from floor to fitting.

Height of the assessed surface.

Published beam angle for the fitting.

Approximate vertical face, mirror or reading surface area receiving the light.

Formula

beam diameter = 2 x effective height x tan(beam angle / 2); target area ratio = beam area / target area

Beam diameter equals two times effective height times tangent of half the beam angle. Target area ratio compares the beam patch with the entered reading surface.

VariableTechnical meaningDesign check
Mounting heightHeight of the bedside fitting or beam origin.Measure from the finished floor or bedhead reference.
Reading planeHeight of the book, tablet or lap surface.The beam patch shrinks as this plane rises.
Beam anglePublished beam angle for the fitting or shade.Shade cutoff and aiming still matter.
Target areaApproximate reading patch area.Use it to compare beam size with the actual task.
Coverage areaCalculated circular beam area.Geometry only, not a lux or glare result.

Related calculators

Related guides

Related tables

Related terms

Related pages