LED strip cut length and reel calculator
Strip only cuts at its marked points, and a cove rarely measures a whole number of them. Enter the runs and the model to see each run at its nearest cut point, the reels to order and the feed points, connectors, channel sticks and end caps that go with them.
Runs to a bill of materials
Pick the model, list the runs, choose the channel. Every length comes back rounded to the model's cut unit, short of the space and over it, so you can decide which way to go.
What the list counts, and what it leaves out
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01
Rounding to the cut unit
Each run is shown twice: rounded down to the last cut point that fits inside the space, and rounded up to the first one that covers it. Strip cannot be cut between points, so one of these two is what gets installed.
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02
Reels and splices
A run longer than one reel is spliced from two pieces. The total to order is the rounded-up runs plus one cut unit per splice for the joint, divided by the reel length and rounded up.
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03
Feeds, connectors and channel
Feed points come from the model's run limit per feed. Each feed is a wire-to-strip connection, each splice a strip-to-strip one. Channel sticks are whole 2 m or 3 m lengths per run, with two end caps per run.
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What it leaves out
Mounting clips, driver and controller counts, cable, and the mitre cuts at corners. Voltage drop in the feed wire and driver sizing have their own calculators, linked below.
The guides behind the numbers
Order LED Strip by Room, Not by Reel, With a Cut Schedule a Factory Can Fill
How to Quote an LED Strip Lighting Job Without Losing the Margin
Four Limits of Free-Cut LED Strip for Signs and Millwork
LED Strip Installation Starts on the Bench, Not on the Ceiling
How to Size an LED Strip Power Supply, From Watts to Class 2 Limits
Why Does the Far End of an LED Strip Go Dim?
Reading the list
Should I round a run down or up?
Down when the strip sits inside a cove or channel with fixed ends, because the next cut point would not fit. Up when the ends are open or the strip runs behind a fascia, so the light reaches the corner. The list shows both so you can decide run by run.
Why does the cut unit change with the voltage?
A 12V strip repeats its circuit every three LEDs and a 24V strip every six, so the 24V version of the same model has a cut unit twice as long. Pick the voltage first and the cut unit follows the spec table.
What counts as a feed point?
A place where the driver cable lands on the strip. The model's run limit per feed sets how often it is needed; a 32 ft run on a strip limited to 16 ft per feed needs two feeds, not one at the end.
Are the reel lengths exact?
They are our standard supply lengths. Custom lengths, pre-wired leads and pre-cut pieces are made to order, so if the list shows a lot of waste, send the runs and we quote the pieces instead of reels.
Does this include the driver?
No. The connected load at the bottom of the list goes into the power supply calculator, which returns the driver rating and how many Class 2 outputs the job needs.
Send the list and the drawing
Paste the list into the form with the reflected ceiling plan. An engineer confirms the cut lengths, the reels or pre-cut pieces, and the feed points, in writing.
- 1 reel minimum
- Drawings welcome
- US-based support