Can Light Calculator
Calculate the number of cans needed to light a room based on room dimensions, can spacing, and light specifications.
Published by:
isCalculator Editorial Team
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How to use this tool?
This calculator determines the number of can lights (recessed lights) needed for a room based on both desired brightness and even spacing.
- Enter Room Dimensions – Input the Length and Width in feet (e.g., 20 and 15).
- Set Spacing – Enter the distance between cans in feet (e.g., 4). This ensures even light distribution.
- Specify Light Output – Enter the Lumens per Can (e.g., 800). Check your bulb’s packaging.
- Set Brightness Goal – Enter the Desired Footcandles (fc). Typical values: 20–30 for living rooms, 30–50 for kitchens.
- Click Calculate – The result shows the recommended number of cans, considering both brightness and spacing.
Tip: All inputs must be positive numbers. Footcandles must be between 1 and 100. The calculator uses feet (imperial).
Previous Results
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Frequently Asked Questions
A can light, also known as a recessed light or downlight, is a light fixture installed into a hollow opening in a ceiling. It provides ambient or task lighting.
The calculator uses two methods: one based on desired footcandles (total lumens needed = footcandles × area) and one based on spacing (number of cans that fit in the grid). The final result is the larger of the two to ensure adequate lighting.
A footcandle is a unit of illuminance equal to one lumen per square foot. It measures how bright a light appears on a surface.