Formula
- Use the units shown beside each field.
- Results update automatically whenever you change an input.
- Displayed values use up to four decimal places, or scientific notation for very small or large numbers. Calculations use standard floating-point arithmetic; exact integer and fraction tools identify their own precision rules.
- Geometric grid only, with half-cell wall offsets. Does not assess lux, beam overlap, glare or required lighting performance.
Example Calculation
- Room length: 6 m
- Room width: 4 m
- Maximum grid cell width: 2 m
Room length = 6 m; Room width = 4 m; Maximum grid cell width = 2 m. Primary result: 6.
Frequently asked questions
How do I use this calculator?
Enter room length, room width, maximum grid cell width. The result updates automatically. Use Reset to restore the example values.
What method does it use?
columns=ceil(length/max spacing); rows=ceil(width/max spacing); place each light at cell center.. Geometric grid only, with half-cell wall offsets. Does not assess lux, beam overlap, glare or required lighting performance.
Why might a rounded result differ?
The calculation keeps full numeric precision internally, then rounds the displayed result. Rounding intermediate steps by hand can produce a slightly different answer.
Are my inputs saved online?
No. This calculator processes your inputs in your browser. A recently used list stores only calculator names on this device, not your entered values.
Check the assumptions and units before using this result. Read about calculation methods.