Coax loss chart
Matched-line attenuation of common coax cables at the ham bands from 160 m to 23 cm, from the manufacturers' datasheets. For your own frequency, length, SWR and power, use the calculator.
Indicative values; verify before use.
Attenuation in dB per 100 m (A4 / metric)
| Cable | 1.8 MHz 160 m | 3.5 MHz 80 m | 7 MHz 40 m | 14 MHz 20 m | 21 MHz 15 m | 28 MHz 10 m | 50 MHz 6 m | 145 MHz 2 m | 435 MHz 70 cm | 1296 MHz 23 cm | Method | Source |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Times Microwave LMR-400 | 0.54* | 0.75* | 1.07* | 1.51* | 1.86* | 2.15* | 2.88 | 4.95 | 8.74 | 15.5 | datasheet formula | datasheet [1], 2026-11-03 |
| Belden 8216 (RG-174 type) | 7.18 | 8.42 | 9.94 | 12.2 | 14.0 | 15.5 | 19.0 | 34.1 | 65.7 | 140.0* | fitted to datasheet points | datasheet [2], 2026-11-03 |
| Belden 84316 (RG-316 type) | 4.84 | 6.12 | 7.81 | 10.3 | 12.4 | 14.1 | 18.4 | 33.2 | 60.1 | 110.2 | fitted to datasheet points | datasheet [3], 2026-11-03 |
| Belden 8240 (RG-58 type) | 1.37 | 2.00 | 2.95 | 4.28 | 5.27 | 6.10 | 8.20 | 15.3 | 29.0 | 54.7* | fitted to datasheet points | datasheet [4], 2026-11-03 |
| Belden 9258 (RG-8X type) | 1.30 | 1.79 | 2.49 | 3.52 | 4.36 | 5.08 | 6.89 | 12.4 | 22.7 | 41.1* | fitted to datasheet points | datasheet [5], 2026-11-03 |
| Belden 8267 (RG-213 type) | 0.75 | 1.06 | 1.50 | 2.16 | 2.68 | 3.13 | 4.27 | 7.53 | 14.4 | 31.6 | fitted to datasheet points | datasheet [6], 2026-11-03 |
| Belden 9913 (RG-8 type) | 0.94* | 1.17* | 1.46 | 1.90 | 2.26 | 2.56 | 3.28 | 5.26 | 8.96 | 17.2* | fitted to datasheet points | datasheet [7], 2026-11-03 |
Attenuation in dB per 100 ft (Letter / US)
| Cable | 1.8 MHz 160 m | 3.5 MHz 80 m | 7 MHz 40 m | 14 MHz 20 m | 21 MHz 15 m | 28 MHz 10 m | 50 MHz 6 m | 145 MHz 2 m | 435 MHz 70 cm | 1296 MHz 23 cm | Method | Source |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Times Microwave LMR-400 | 0.16* | 0.23* | 0.33* | 0.46* | 0.57* | 0.65* | 0.88 | 1.51 | 2.66 | 4.74 | datasheet formula | datasheet [1], 2026-11-03 |
| Belden 8216 (RG-174 type) | 2.19 | 2.57 | 3.03 | 3.71 | 4.28 | 4.73 | 5.80 | 10.4 | 20.0 | 42.7* | fitted to datasheet points | datasheet [2], 2026-11-03 |
| Belden 84316 (RG-316 type) | 1.48 | 1.87 | 2.38 | 3.14 | 3.78 | 4.31 | 5.60 | 10.1 | 18.3 | 33.6 | fitted to datasheet points | datasheet [3], 2026-11-03 |
| Belden 8240 (RG-58 type) | 0.42 | 0.61 | 0.90 | 1.31 | 1.61 | 1.86 | 2.50 | 4.68 | 8.83 | 16.7* | fitted to datasheet points | datasheet [4], 2026-11-03 |
| Belden 9258 (RG-8X type) | 0.40 | 0.55 | 0.76 | 1.07 | 1.33 | 1.55 | 2.10 | 3.79 | 6.93 | 12.5* | fitted to datasheet points | datasheet [5], 2026-11-03 |
| Belden 8267 (RG-213 type) | 0.23 | 0.32 | 0.46 | 0.66 | 0.82 | 0.95 | 1.30 | 2.29 | 4.39 | 9.62 | fitted to datasheet points | datasheet [6], 2026-11-03 |
| Belden 9913 (RG-8 type) | 0.29* | 0.36* | 0.45 | 0.58 | 0.69 | 0.78 | 1.00 | 1.60 | 2.73 | 5.24* | fitted to datasheet points | datasheet [7], 2026-11-03 |
Loss for another length: dB/100 m × length in m / 100 (10 m = one tenth of the dB/100 m value). Matched line (SWR 1:1); with SWR the loss is higher, see the calculator. * Outside the frequency range of the datasheet's attenuation table; extended from the nearest datasheet points (rough estimate).
Indicative calculation; verify before use. Attenuation is the manufacturer's nominal matched-line value for new cable at the datasheet's reference temperature. Connectors, ageing, moisture and installation add loss. The SWR correction is an approximation. This page does not check whether a cable can safely carry a given power; see the manufacturer's datasheet.
LMR is a registered trademark of Times Microwave Systems. Other product names are trademarks of their respective owners. Ohmsums is not affiliated with or endorsed by any cable maker.
Method: "datasheet formula" = A = K1 × √f + K2 × f with the manufacturer's constants. "fitted to datasheet points" = straight lines between neighbouring datasheet values on log–log axes, exact at every datasheet frequency. dB/100 m = dB/100 ft × 3.2808. Sources (checked 2026-11-03):
- [1] Times Microwave LMR-400 (datasheet formula: A = 0.12229 × √f + 0.00026 × f dB/100 ft), retrieved 2026-11-03: https://timesmicrowave.com/wp-content/uploads/2022/06/lmr-400-datasheet.pdf
- [2] Belden 8216 (RG-174 type) (fitted to datasheet points: 9 points, 1–1000 MHz), retrieved 2026-11-03: https://catalog.belden.com/techdata/EN/8216_techdata.pdf
- [3] Belden 84316 (RG-316 type) (fitted to datasheet points: 13 points, 1–3000 MHz), retrieved 2026-11-03: https://catalog.belden.com/techdata/EN/84316_techdata.pdf
- [4] Belden 8240 (RG-58 type) (fitted to datasheet points: 9 points, 1–1000 MHz), retrieved 2026-11-03: https://catalog.belden.com/techdata/EN/8240_techdata.pdf
- [5] Belden 9258 (RG-8X type) (fitted to datasheet points: 9 points, 1–1000 MHz), retrieved 2026-11-03: https://catalog.belden.com/techdata/EN/9258_techdata.pdf
- [6] Belden 8267 (RG-213 type) (fitted to datasheet points: 10 points, 1–4000 MHz), retrieved 2026-11-03: https://catalog.belden.com/techdata/EN/8267_techdata.pdf
- [7] Belden 9913 (RG-8 type) (fitted to datasheet points: 9 points, 5–1000 MHz), retrieved 2026-11-03: https://catalog.belden.com/techdata/EN/9913_techdata.pdf
Ohmsums. Indicative values; verify before use.