IP66 vs IPX4
Head-to-head comparison of two IEC 60529 ingress protection ratings.
IP66 and IPX4 are both IEC 60529 ingress protection codes, but they differ in solid-object protection (level 6 vs 0) and liquid protection (level 6 vs 4). IP66 is rated for dust-tight and powerful water jets (12.5 mm nozzle), while IPX4 provides no protection and splashing water (all directions).
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).
IPX4 (solid protection not specified) resists splashing water from any direction. A common minimum for bathroom and outdoor-covered appliances where dust sealing is not required.
Detailed comparison
The stronger rating on each row is highlighted in emerald.
Solid protection (first digit)
IP66
6 — Dust-Tight
IPX4
0 — No Protection
Liquid protection (second digit)
IP66
6 — Powerful Water Jets (12.5 mm nozzle)
IPX4
4 — Splashing Water (all directions)
Dust-tight
IP66
Yes
IPX4
No
Water-jet resistant
IP66
Yes
IPX4
No
Submersible
IP66
No
IPX4
No
Outdoor suitable
IP66
Yes
IPX4
Yes
The exact difference (IP66 vs IPX4)
Solid protection
IP66
Level 6 — Dust-Tight
IPX4
Level 0 — No Protection
IP66 provides "Dust-Tight" (level 6), while IPX4 provides "No Protection" (level 0). IP66 is 6 levels higher.
Liquid protection
IP66
Level 6 — Powerful Water Jets (12.5 mm nozzle)
IPX4
Level 4 — Splashing Water (all directions)
IP66 handles 100 kPa (Powerful Water Jets (12.5 mm nozzle)), while IPX4 handles 50–100 kPa (Splashing Water (all directions)). IP66 provides 2 levels more liquid protection.
NEMA equivalents
No direct NEMA equivalent.
Recommendation
IP66 offers higher overall protection than IPX4. Choose IP66 for harsher environments; IPX4 may suffice for milder conditions and can be more cost-effective.