Everyday recessed lighting problems come down to one relationship between columns of lighting fixtures, surface length (a), rows of lighting fixtures and surface width (b). This calculator turns those numbers into centered lighting’s horizontal offset (xo), centered lighting’s vertical offset (yo) and centered lightings’ spacing (yi), with the working shown so you can check the result rather than simply trust it.
What Is the Recessed Lighting Calculator?
The recessed lighting calculator turns columns of lighting fixtures, surface length (a), rows of lighting fixtures and surface width (b) into centered lighting's horizontal offset (xo), centered lighting's vertical offset (yo) and centered lightings' spacing (yi).
It is a quick way to get from the numbers you have to the number you need, without setting up a spreadsheet or reaching for a formula.
How the Recessed Lighting Works
Each result follows from the ones before it, and the calculator shows every step, so a surprising answer can be traced back to the input that caused it.
Round your inputs to the precision you actually know, and keep more precision than that in the intermediate steps.
Getting a Result You Can Trust
Run the calculation twice with slightly different inputs. A sensible calculator moves its output in proportion; a wild change points to a unit or a decimal point problem in what you entered.
Write the inputs down next to the answer. It takes a moment and it is the difference between a number you can explain and one you cannot.
A Worked Example
Working through an example, with columns of lighting fixtures set to 1, surface length (a) set to 10, rows of lighting fixtures set to 1, the calculator returns outer row offset a o of 5, and row spacing a i of 10, and outer column offset b o of 2.5. Substitute your own figures and the same steps produce the same kind of answer.
Frequently Asked Questions
What do I need to work out centered lighting's horizontal offset (xo)?
Enter columns of lighting fixtures, surface length (a), rows of lighting fixtures and surface width (b). The calculator then works through the relationship and reports centered lighting's horizontal offset (xo), centered lighting's vertical offset (yo) and centered lightings' spacing (yi).
What does the recessed lighting actually calculate?
It takes columns of lighting fixtures, surface length (a), rows of lighting fixtures and surface width (b) and converts them into centered lighting's horizontal offset (xo), centered lighting's vertical offset (yo) and centered lightings' spacing (yi) using the standard relationship for this problem. Each step is applied in turn, so every output is traceable back to the numbers you typed in.
How should I enter columns of lighting fixtures?
Use the value you actually have, in the unit shown next to the field. Enter every value in the same unit system. The calculator assumes the figures you supply are consistent, so it cannot correct a mistake that happens before the calculation starts.
Do I have to fill in every field?
Only the fields a particular result depends on. If you leave one blank, the results that need it simply show a note instead of a number, and everything else still works.
Why does a small change in one value move the answer so much?
That happens when an output depends on a ratio, because dividing by a small number magnifies any change in it. Check the units first, then check whether the value you entered is in the range the relationship was designed for.