For most home TV and cable internet connections, RG6 is the common size. For long 75-ohm runs, RG11 is larger and lower loss. For RF, radio, and test equipment, 50-ohm coax types such as RG58, RG8, RG213, and RG174 are common.
Coax Cable Diameter Chart
| Cable Type | Approx. Outer Diameter | Impedance | Typical Use |
|---|---|---|---|
| RG174 | 2.5 mm / 0.10 in | 50 ohm | Small RF pigtails, compact antenna leads |
| RG58 | 5.0 mm / 0.20 in | 50 ohm | RF, radio, short test cables |
| RG59 | 6.1 mm / 0.24 in | 75 ohm | Older video, CCTV, short analog runs |
| RG6 | 6.9 mm / 0.27 in | 75 ohm | TV, cable internet, satellite, antenna |
| RG8 | 10.3 mm / 0.40 in | 50 ohm | RF transmission, radio |
| RG11 | 10.3 mm / 0.40 in | 75 ohm | Long cable TV, satellite, broadband runs |
| RG213 | 10.3 mm / 0.40 in | 50 ohm | RF transmission, antenna feed lines |
These sizes are approximate. Actual diameter can vary by manufacturer, jacket material, shielding, plenum rating, and outdoor or direct-burial construction.
Important Accuracy Note
Coax cable diameter charts should be treated as approximate selection guides, not final engineering specifications. The same broad cable family can have different outside diameters depending on:
| Variable | How It Changes Cable Size |
|---|---|
| Shield count | Quad-shield cable is often larger than standard shielded cable |
| Jacket rating | Plenum, riser, outdoor, and direct-burial jackets can differ |
| Manufacturer | Commercial RG labels do not guarantee identical construction |
| Connector system | Compression, crimp, and clamp connectors may require exact cable dimensions |
| Conductor type | Solid, stranded, copper, and copper-clad steel designs may differ |
For connector selection, use the cable manufacturer’s datasheet rather than only a general chart.
How Coaxial Cable Sizes Are Measured
Coaxial cable size usually refers to the outside diameter of the finished cable, including the outer jacket. This matters because it affects:
- Connector compatibility
- Bend radius
- Cable routing
- Pulling through walls or conduit
- Signal loss over distance
- Flexibility
The center conductor size, dielectric, shield, and jacket also matter, but the outside diameter is the easiest physical size to compare.
RG6 Diameter
RG6 coaxial cable is about 6.9 mm or 0.27 in in outer diameter, depending on construction. It is the standard size for most modern home TV, satellite, antenna, and cable modem connections. For TV-specific installation choices, see the best coaxial cable for TV article.
| RG6 Feature | Detail |
|---|---|
| Approx. diameter | 6.9 mm / 0.27 in |
| Impedance | 75 ohm |
| Common connector | F-type |
| Common use | TV, satellite, antenna, cable internet |
Quad-shield RG6 may be slightly larger than standard RG6 and requires compatible connectors.
RG59 Diameter
RG59 coaxial cable is about 6.1 mm or 0.24 in in outer diameter. It is slightly thinner than RG6 and is often found in older video and CCTV installations.
| RG59 Feature | Detail |
|---|---|
| Approx. diameter | 6.1 mm / 0.24 in |
| Impedance | 75 ohm |
| Common connector | BNC, RCA, F-type |
| Common use | Older analog video, CCTV |
RG59 is easier to bend than RG6, but it is usually not preferred for modern high-frequency TV, satellite, or cable internet runs.
RG11 Diameter
RG11 coaxial cable is about 10.3 mm or 0.40 in in outer diameter. It is much thicker than RG6 and is used for long 75-ohm cable runs.
| RG11 Feature | Detail |
|---|---|
| Approx. diameter | 10.3 mm / 0.40 in |
| Impedance | 75 ohm |
| Common connector | F-type |
| Common use | Long cable TV, satellite, broadband, outdoor runs |
RG11 has lower signal loss over long distances, but it is harder to route and bend.
RG58 Diameter
RG58 coaxial cable is about 5.0 mm or 0.20 in in outer diameter. It is a common 50-ohm cable for RF, radio, and short test leads.
| RG58 Feature | Detail |
|---|---|
| Approx. diameter | 5.0 mm / 0.20 in |
| Impedance | 50 ohm |
| Common connector | BNC, SMA, N-type, UHF |
| Common use | Short RF and radio connections |
RG58 is flexible and convenient, but larger 50-ohm cables are better for longer or lower-loss RF runs.
RG174 Diameter
RG174 is much smaller than RG58, at about 2.5 mm or 0.10 in. It is used for short RF pigtails and compact internal connections.
The advantage is flexibility and small size. The disadvantage is higher loss, especially at higher frequencies.
Does Cable Diameter Affect Signal Quality?
Cable diameter can affect signal quality indirectly. Larger coaxial cables often have lower attenuation than smaller cables of the same general category, especially over longer distances and higher frequencies.
However, diameter is not the only factor. Signal performance also depends on:
| Factor | Why It Matters |
|---|---|
| Impedance | Must match the system, usually 50 ohm or 75 ohm |
| Shielding | Reduces interference and signal leakage |
| Conductor material | Affects resistance and performance |
| Dielectric | Affects impedance and loss |
| Frequency | Higher frequencies usually have more loss |
| Cable length | Longer runs lose more signal |
| Connector quality | Poor connectors can cause loss or reflections |
A larger cable is not automatically better for every use. It must match the equipment and installation.
Coax Cable Size vs Signal Loss
In general, longer cable runs and higher frequencies need lower-loss cable. That is why RG11 is often used instead of RG6 for long 75-ohm runs, and why larger 50-ohm RF coax may be used instead of RG58 for long antenna feed lines.
| Situation | Better Cable Choice |
|---|---|
| Short TV patch cable | RG6 |
| Long TV or satellite run | RG11 |
| Short RF test lead | RG58 |
| Longer RF antenna feed | RG8, RG213, or another lower-loss 50-ohm coax |
| Compact internal RF lead | RG174 |
Which Coax Size Should You Choose?
| Need | Recommended Size |
|---|---|
| Home TV or cable modem | RG6 |
| Outdoor antenna run | RG6, or RG11 for long runs |
| Long cable TV distribution | RG11 |
| Older CCTV or analog video | RG59 |
| Short RF test cable | RG58 |
| Long RF antenna cable | RG8, RG213, or other low-loss 50-ohm coax |
| Small internal antenna cable | RG174 |
When in doubt, start with the equipment requirements. The correct impedance and connector type are more important than diameter alone. If you are identifying a loose cable before measuring it, use the guide on what a coax cable looks like.
Connector Fit Checklist
Cable diameter matters most when you are choosing connectors. Before buying connectors for bulk coax, check:
- Cable family, such as RG6, RG59, RG11, or RG58
- Outside jacket diameter
- Dielectric diameter
- Center conductor diameter
- Shield type and shield count
- Connector style: compression, crimp, solder, clamp, or twist-on
- Indoor, outdoor, or weather-sealed requirement
This is especially important for quad-shield RG6 and RG11 because they may not fit connectors intended for standard RG6.
FAQ
What size is RG6 coax cable?
RG6 coaxial cable is typically about 6.9 mm or 0.27 in in outer diameter, but exact size varies by manufacturer and construction.
What size is RG59 coax cable?
RG59 is typically about 6.1 mm or 0.24 in in outer diameter.
What size is RG11 coax cable?
RG11 is typically about 10.3 mm or 0.40 in in outer diameter.
What size is RG58 coax cable?
RG58 is typically about 5.0 mm or 0.20 in in outer diameter.
Is RG11 bigger than RG6?
Yes. RG11 is significantly thicker than RG6 and is usually used for longer runs where lower loss is needed.
Does thicker coax cable mean better signal?
Not always. Thicker coax often has lower loss over distance, but the cable must still match the system impedance, connector type, frequency, and installation needs.
Are coax cable sizes exact?
No. Published diameters are usually approximate. Jacket type, shielding, rating, and manufacturer design can change the actual size.
Related Reading
For usage recommendations by TV, internet, and Ethernet adapter scenarios, see the full Coaxial Cable Guide. For modem, router, and MoCA use cases, see coaxial cable vs Ethernet cable.
