IP and IK ratings for outdoor lighting

The short answer

The IP rating tells you how well a luminaire keeps out dust and water. The IK rating tells you how well it resists impact. For most wall-mounted exterior lighting, IP65 or IP66 is a sensible minimum. Luminaires at ground level, where water can pool, are better at IP67. In-ground and underwater luminaires need ratings, and load or depth limits, designed for that use. Always check the specific product, because the right rating depends on where and how it’s installed.

IP ratings (IEC 60529)

An IP code has two digits, for example IP66. The first is protection against solid objects and dust; the second is protection against water. An X in place of a digit (such as IPX7) means that part wasn’t tested or specified.

First digit: solids and dust

Digit	Protection
0	Not protected
1	Objects larger than 50 mm (for example the back of a hand)
2	Objects larger than 12.5 mm (fingers)
3	Objects larger than 2.5 mm (tools, thick wires)
4	Objects larger than 1 mm (thin wires, screws)
5	Dust-protected: some dust may enter, but not enough to interfere with operation
6	Dust-tight: no dust enters

Second digit: water

Digit	Protection
0	Not protected
1	Vertically dripping water
2	Dripping water when tilted up to 15°
3	Spraying water, up to 60° from vertical
4	Splashing water from any direction
5	Water jets from any direction
6	Powerful water jets from any direction
7	Temporary immersion, up to 1 m for 30 minutes
8	Continuous immersion, under conditions stated by the manufacturer that are more severe than for 7

What the common outdoor ratings mean in practice

Rating	In practice
IP65	Dust-tight and protected against water jets. Suitable for most walls and soffits exposed to rain.
IP66	Dust-tight and protected against powerful jets. A good choice for exposed elevations, coastal sites and anywhere that may be pressure-washed.
IP67	Dust-tight and protected against short-term immersion. Suits ground-level luminaires where water can puddle or flood briefly.
IP68	Dust-tight and protected against continuous immersion to a depth and time the manufacturer states. Needed for underwater use, and often for in-ground luminaires. Always check the stated depth.

One point that catches people out: under IEC 60529, a product tested only for immersion (7 or 8) isn’t automatically proven against jets (5 or 6). That’s why you’ll see dual ratings such as IP66/IP67 or IP66/IP68 on products meant for both.

IK ratings (IEC 62262 / EN 62262)

The IK code describes resistance to mechanical impact, measured as the energy of a blow in joules.

Code	Impact energy
IK00	Not protected
IK01	0.14 J
IK02	0.2 J
IK03	0.35 J
IK04	0.5 J
IK05	0.7 J
IK06	1 J
IK07	2 J
IK08	5 J
IK09	10 J
IK10	20 J

Higher numbers suit luminaires within reach of the public, in schools and parks, near car parks, and anywhere vandalism is a concern. Out-of-reach luminaires at high level rarely need a high IK rating.

Which rating where?

These are general guides. Always check the product’s own data and installation instructions.

Location	What to look for
Wall-mounted, out of reach	IP65 or IP66. IK not usually critical.
Wall-mounted, within reach	IP65 or IP66, with a higher IK rating such as IK08 or above.
Ground level (spikes, surface-mounted uplights)	IP67 or dual-rated, because rain, irrigation and puddles reach them.
In-ground, pedestrian areas	IP67 or IP68, a high IK rating, and a static load rating suitable for foot traffic. Check the glass surface temperature too.
In-ground, drive-over	IP67 or IP68 and a static load rating for vehicles. The IK rating covers impact only, not the weight of a vehicle standing on it, so the load rating matters. Good drainage beneath the luminaire is essential.
Fountains, ponds and pools	IP68 rated for the actual depth, materials suitable for the water (chlorinated, salt or fresh), and wiring that meets the relevant electrical rules. In the UK, BS 7671 has specific requirements for swimming pools and fountains. Always check the product and take advice from the installing electrician.

Cable entries and glands

A luminaire’s IP rating only holds if the cable entry is made correctly.

• Use the gland supplied or specified, sized for the cable’s outer diameter. A gland that’s too big for the cable won’t seal.
• Use cable of the type stated, usually round, sheathed outdoor cable. Flat or twin cables won’t seal in a round gland.
• Make joints in rated connectors or junction boxes, not with tape. Gel-filled or resin connectors are common for buried and in-ground joints.
• Form a drip loop so water runs off the cable before it reaches the gland.
• Don’t leave cable ends exposed. Water can travel along the inside of a cable by capillary action into a luminaire, even if the gland seals perfectly.
• In-ground luminaires need drainage, such as a gravel soakaway beneath the housing, so water doesn’t sit around them.

How we can help

Tell us where each luminaire will go and we’ll check the IP, IK and load ratings against the location. Start a project.

Sources: IEC 60529, Degrees of protection provided by enclosures (IP Code); IEC 62262 / EN 62262, Degrees of protection provided by enclosures for electrical equipment against external mechanical impacts (IK code); BS 7671, Requirements for Electrical Installations.