Published on 10/13/2026
A harness designer needs to route eight RF cables through a 25 mm conduit and keep the bundle under 600 g. Datasheets list diameter and weight in different units, and every maker rounds differently. A single chart helps: outside diameter in millimeters and weight in grams per meter for the common RG and LMR cables.
Short answer: RG316 is about 2.5 mm and 9 g/m, RG58 about 4.95 mm and 38 g/m, RG213 about 10.3 mm and 150 g/m, and LMR-400 about 10.3 mm and 100 g/m. The chart below covers 16 cable types.
Values are typical nominal figures, with weights within about 15 percent of datasheet values. Confirm against the maker's datasheet for any build that is limited by weight or space.
On This Page
| Cable | Impedance | Outer diameter (mm) | Weight (g/m, approx.) | Jacket |
|---|---|---|---|---|
| RG178 | 50 ohm | 1.8 | 4 | FEP |
| RG179 | 75 ohm | 2.5 | 8 | FEP |
| RG174 | 50 ohm | 2.8 | 11 | PVC |
| RG316 | 50 ohm | 2.5 | 9 | FEP |
| RG316D (double shield) | 50 ohm | 2.9 | 14 | FEP |
| RG405 / 0.086 in semi-rigid | 50 ohm | 2.2 | 13 | Bare tin or copper |
| RG402 / 0.141 in semi-rigid | 50 ohm | 3.6 | 30 | Bare tin or copper |
| RG58 | 50 ohm | 4.95 | 38 | PVC |
| RG142 | 50 ohm | 4.95 | 55 | FEP |
| RG400 | 50 ohm | 4.95 | 50 | FEP |
| RG223 | 50 ohm | 5.4 | 55 | PVC |
| RG59 | 75 ohm | 6.15 | 55 | PVC |
| RG213 | 50 ohm | 10.3 | 150 | PVC |
| RG214 | 50 ohm | 10.8 | 200 | PVC |
| LMR-195 class | 50 ohm | 4.95 | 25 | PE |
| LMR-240 class | 50 ohm | 6.1 | 39 | PE |
| LMR-400 class | 50 ohm | 10.3 | 100 | PE |
| LMR-600 class | 50 ohm | 14.9 | 165 | PE |
Semi-rigid cable is listed by nominal outer conductor diameter. Weights depend on the outer conductor material (copper, tin-plated copper, aluminum) and plating.
Step 01
Conduit and bundle size
Add the outer diameters in a row, then add 20 percent for spacing. Round bundles need about 1.3 times the sum of areas.
Step 02
Weight budget
Multiply g/m by the length. A 3 m RG316 jumper weighs about 27 g; a 3 m RG213 run is 450 g.
Step 03
Connector fit
Crimp ferrules are sized to the cable outer diameter, so verify the connector part number against the cable.
Step 04
Bend radius
Typical minimum bend radius is 5 to 10 times the outer diameter for flexible cables.
Key idea: Diameter drives loss. A cable twice as thick has about half the loss at the same frequency, but weighs three to four times as much.
We can recommend a lighter assembly
Tell us the frequency, length and weight limit. Every assembly is VNA-swept for VSWR and insertion loss before shipment.
Talk to an Engineer| Class | Diameter | Weight | Loss at 2.4 GHz (dB/m, approx.) |
|---|---|---|---|
| Micro (RG178, RG316) | Smallest | Lightest | 1.4 to 2.3 |
| Mid (RG58, LMR-195) | About 5 mm | 25 to 38 g/m | 0.8 to 1.2 |
| Large (RG213, LMR-400) | About 10 mm | 100 to 150 g/m | 0.36 to 0.74 |
For loss numbers across frequencies, see the attenuation chart in this series.
Avoid
What is the diameter of RG58?
About 4.95 mm (0.195 in).
How much does RG316 weigh per meter?
About 9 g per meter.
What is the diameter of RG213?
About 10.3 mm (0.405 in).
Which is thinner, RG174 or RG316?
RG316 at about 2.5 mm, versus 2.8 mm for RG174.
How heavy is LMR-400?
About 100 g per meter, roughly two thirds of RG213.
Are these numbers exact?
No. They are typical nominal values, so check the datasheet for your cable.
Choose the smallest cable that still meets your loss budget, then check the bundle size, weight and connector fit. Use the chart for a first pass and the datasheet for the final design.
SigmaRF builds assemblies on all of these cable types in India (Vadodara) and the USA (Cleveland area), VNA-swept before shipment, with lead times as short as 2 days.
Get a quote on your cable
Send the cable type, length and connectors.
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