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Buying Guide · 5 min read

LED Strip Lights Buying Guide: Voltage, Density, CRI & Waterproofing

LED strip lights are one of the most versatile lighting products available — but also one of the most confusing to specify. This guide covers everything from voltage and LED density to CRI, IP ratings, aluminium profiles and driver sizing.

Published 15 July 2026 · Updated October 2026 · By LED Warehouse Direct

Step 1 — Choose Your Voltage: 12V or 24V?

LED strips run on low-voltage DC power (12V or 24V) supplied by a driver (transformer). The voltage affects maximum run length, LED density and overall performance.

12V

Lower cost drivers
Widely available accessories
Good for short runs up to 5m
–Voltage drop over longer runs
–Lower max wattage per metre
–Less suitable for commercial use

24V

Longer runs up to 10m
More LEDs per metre
Better for commercial/retail
Less voltage drop
–Slightly higher driver cost
–Less common in DIY market

Step 2 — LED Density (LEDs per Metre)

LED density affects light output, smoothness and hotspot visibility. Higher density strips produce more even light with fewer visible dots.

DensityTypical UseNotes
30 LEDs/mAccent lighting, under-cabinet (hidden)Visible dots if strip is exposed
60 LEDs/mGeneral cove lighting, under-cabinetGood balance of cost and quality
120 LEDs/mRetail displays, hospitality, visible stripsVery smooth output, minimal hotspots
240 LEDs/mHigh-end retail, art galleries, feature wallsPremium, near-seamless output

Step 3 — CRI (Colour Rendering Index)

CRI measures how accurately colours appear under the light. For most applications, CRI 80+ is fine. For colour-critical environments, choose higher:

CRI 80+

General residential and commercial use. Acceptable colour rendering.

CRI 90+

Retail, hospitality, kitchens. Noticeably better colour accuracy — food and products look more appealing.

CRI 95+

Art galleries, jewellery, high-end retail, photography studios. Near-perfect colour rendering.

Step 4 — IP Rating for Your Environment

IP20

Dry indoor use. Living rooms, bedrooms, offices, dry coves.

IP44

Splash-proof. Bathroom zones, covered outdoor areas.

IP65

Silicone-coated. Kitchens, outdoor use, areas subject to cleaning.

IP67/68

Fully waterproof. Outdoor ground-level, ponds, fully exposed installations.

Step 5 — Aluminium Profiles and Channels

Aluminium extrusion profiles protect the strip, diffuse the light for a seamless glow and act as a heat sink to extend LED lifespan. They are strongly recommended for any permanent installation. Common profile types include surface-mounted, recessed, corner and under-cabinet channels.

Step 6 — Driver Sizing

Always size your driver at 80% of its maximum capacity to allow headroom and extend driver life. For example, for 10 metres of 14.4W/m strip (144W total), use a 180W driver minimum.

Driver Sizing Formula

Strip length (m) × W/m = Total watts

Total watts ÷ 0.8 = Minimum driver wattage

Example: 8m × 14.4W/m = 115.2W ÷ 0.8 = 144W driver minimum

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Common Questions

What is the difference between 12V and 24V LED strip lights?

12V LED strips are suitable for shorter runs (up to 5m per driver) and are common in residential applications. 24V strips can run longer lengths (up to 10m per driver) with less voltage drop, making them better for commercial and retail use. 24V strips also tend to have more LEDs per metre, producing a smoother, more even light output.

What does CRI mean for LED strip lights?

CRI (Colour Rendering Index) measures how accurately a light source renders colours compared to natural daylight (CRI 100). For general use, CRI 80+ is acceptable. For retail, hospitality, art galleries or anywhere colour accuracy matters, choose CRI 90+ or CRI 95+. Higher CRI strips typically cost more but produce noticeably better colour rendering.

Can LED strip lights be cut to length?

Yes. LED strip lights can be cut at marked cutting points, which are typically every 50mm or 100mm depending on the strip type. Always cut at the marked scissors symbol — cutting elsewhere will damage the circuit. After cutting, the end can be capped or connected to another strip using a compatible connector.

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