The calculator estimates the total strip length needed for a cove run, then rounds it up to the nearest cut point and converts it into reels.
- Choose your unit and layout method.
- Enter room dimensions or custom segment lengths.
- Select coverage (full, sides, or percent) if using a rectangle.
- Add corner allowance and a small extra percent for connectors.
- Set cut interval and reel length based on your strip product.
- Press Calculate to see required length and reels.
- Use the CSV/PDF buttons to save your plan.
| Scenario | Inputs | Output (rounded) |
|---|---|---|
| Herb bench room perimeter |
Rectangle 6 m × 3 m, full perimeter; corner allowance 0.03 m; extra 5%; cut 0.05 m; reel 5 m |
18.90 m strip; 4 reels; ~1.10 m waste |
| Seedling rack partial run |
Rectangle 4 m × 2 m, 50% coverage; corner allowance 0.02 m; extra 8%; cut 0.05 m; reel 5 m |
6.55 m strip; 2 reels; ~3.45 m waste |
| Custom shelf lines |
Segments: 1.5, 1.5, 2.0, 2.0 m; corners 6; corner allowance 0.02 m; extra 5%; cut 0.05 m; reel 5 m |
7.20 m strip; 2 reels; ~2.80 m waste |
Examples are illustrative and may differ from your chosen options.
Light-line planning for grow zones
Cove lighting is often used to soften shadows along benches, racks, and greenhouse walls. A strip around a 6 m × 3 m zone produces a 18 m base run before allowances. Planning the run length first helps you select the right reel count and reduces splices that can corrode in gardens. For propagation trays, a 30–50 cm offset from the canopy keeps edges without bleaching, supporting year-round reliability.
Perimeter versus segment layouts
The rectangle method uses perimeter = 2 × (L + W). If you only light two sides of a 4 m × 2 m space, the base run becomes 6 m instead of 12 m. For shelving, the segment method sums straight runs, such as 1.5 + 1.5 + 2.0 + 2.0 = 7.0 m, and then adds corner handling separately.
Corner allowance and service slack
Strips rarely sit perfectly tight at turns. Many growers add 0.02–0.05 m per corner to keep bend radii gentle and to protect solder joints. Add a fixed service loop near drivers, timers, or dimmers, commonly 0.3–0.6 m, so you can reterminate leads after cleaning or seasonal rearrangements.
Extras, cut points, and rounding
Connectors, clips, and mistakes consume length. A practical extra percentage is 5–10% for small rooms and up to 15% for complex racks. Strips also cut only at marked intervals, often 0.025 m, 0.05 m, or 0.10 m depending on voltage and diode spacing. Rounding up to the nearest cut point prevents unusable offcuts. When layouts include jumpers, budget one cut segment per jumper for clean terminations.
Reels, waste, and purchasing decisions
Retail reels are commonly 5 m, 10 m, or 20 m. If your rounded requirement is 18.9 m and you buy 5 m reels, you need 4 reels (20 m total) and the expected waste is about 1.1 m. If 10 m reels are available, 2 reels may reduce connectors but increase leftover. Use the waste estimate to compare reel options before ordering.
FAQs
1) Should I measure from wall to wall or around obstacles?
Measure the actual path where the strip will sit. If pipes, posts, or shelving interrupt the line, treat them as separate segments and add a small fixed extra for rerouting.
2) How much extra percent is typical for a small grow room?
Most installations work well with 5–10% extra. Use the higher end if you expect rework, multiple connectors, or frequent layout changes during crop rotations.
3) What corner allowance should I start with?
Start with 0.02 m per corner for gentle bends. Increase to 0.03–0.05 m if you use rigid channels, thicker waterproof strips, or wider bend radii.
4) Why does the calculator round up to a cut interval?
LED strips can only be cut at marked points. Rounding ensures your plan lands on a valid cut location, so every piece can be wired without wasting partial sections.
5) How do I choose a reel length in the inputs?
Use the reel size sold for your strip product, commonly 5 m or 10 m. Matching the input to real packaging gives a realistic reel count and waste estimate.
6) Does this calculator estimate brightness or power needs?
No. It focuses on length planning, reels, and waste. For power, check your strip’s watts per meter and ensure the driver is sized with headroom for temperature and humidity.