IP66 vs IP45
Head-to-head comparison of two IEC 60529 ingress protection ratings.
IP66 and IP45 are both IEC 60529 ingress protection codes, but they differ in solid-object protection (level 6 vs 4) and liquid protection (level 6 vs 5). IP66 is rated for dust-tight and powerful water jets (12.5 mm nozzle), while IP45 provides > 1 mm — small wires and water jets (6.3 mm nozzle).
IP66 is dust-tight and resists powerful water jets (12.5 mm nozzle, 100 kPa). A robust outdoor rating for equipment exposed to heavy rain, storms, or directed high-pressure hosing (but not high-pressure washdown).
IP45 protects against 1 mm solid objects and low-pressure water jets (6.3 mm nozzle, 30 kPa). A mid-range indoor/outdoor-covered rating for equipment that may be rinsed or hosed gently.
Detailed comparison
The stronger rating on each row is highlighted in emerald.
Solid protection (first digit)
IP66
6 — Dust-Tight
IP45
4 — > 1 mm — Small Wires
Liquid protection (second digit)
IP66
6 — Powerful Water Jets (12.5 mm nozzle)
IP45
5 — Water Jets (6.3 mm nozzle)
Dust-tight
IP66
Yes
IP45
No
Water-jet resistant
IP66
Yes
IP45
Yes
Submersible
IP66
No
IP45
No
Outdoor suitable
IP66
Yes
IP45
Yes
The exact difference (IP66 vs IP45)
Solid protection
IP66
Level 6 — Dust-Tight
IP45
Level 4 — > 1 mm — Small Wires
IP66 provides "Dust-Tight" (level 6), while IP45 provides "> 1 mm — Small Wires" (level 4). IP66 is 2 levels higher.
Liquid protection
IP66
Level 6 — Powerful Water Jets (12.5 mm nozzle)
IP45
Level 5 — Water Jets (6.3 mm nozzle)
IP66 handles 100 kPa (Powerful Water Jets (12.5 mm nozzle)), while IP45 handles 30 kPa (Water Jets (6.3 mm nozzle)). IP66 provides 1 level more liquid protection.
NEMA equivalents
Recommendation
IP66 offers higher overall protection than IP45. Choose IP66 for harsher environments; IP45 may suffice for milder conditions and can be more cost-effective.