Calculated Cable Loss
Results appear here after submission and stay above the form.
Total Loss
0.00 dB
Loss Per 100 m
0.00 dB
Remaining Power
100.00 %
Suggested Max Length
0.00 m
Input Frequency
0.00 MHz
Cable Run
0.00 m
Estimated End Voltage Ratio
100.00 %
Calculator Inputs
Loss Trend Graph
The curve shows estimated total loss across increasing run lengths at the selected frequency.
Example Data Table
| Cable | Frequency | Length | Attenuation | Connectors | Total Loss |
|---|---|---|---|---|---|
| RG58 | 100 MHz | 30 m | 12.9 dB / 100 m | 2 × 0.10 dB | 4.07 dB |
| RG6 | 450 MHz | 40 m | 8.5 dB / 100 m @ 100 MHz | 2 × 0.10 dB | 7.41 dB |
| LMR-400 | 900 MHz | 25 m | 3.9 dB / 100 m @ 100 MHz | 2 × 0.08 dB | 1.09 dB |
Formula Used
Cable attenuation per 100 m = Reference loss × (Operating frequency ÷ Reference frequency)n × Temperature factor
Temperature factor = 1 + 0.002 × (Temperature − 20)
Cable loss = Attenuation per 100 m × (Cable length in meters ÷ 100)
Total loss = Cable loss + (Connector count × Loss per connector)
Remaining power ratio = 10−Total loss / 10
Voltage ratio = 10−Total loss / 20
This model is useful for planning. Manufacturer datasheets should confirm final design values.
How to Use This Calculator
- Select a cable preset or choose Custom.
- Enter operating frequency and physical cable length.
- Pick the length unit and ambient temperature.
- Review or edit the reference attenuation values.
- Add connector count and loss per connector.
- Set a target maximum allowable loss.
- Press Calculate Loss to show results above the form.
- Use the CSV or PDF buttons to export the summary.
Frequently Asked Questions
1. What does coaxial cable loss mean?
It is the signal reduction that happens as energy travels through the cable. Loss is usually expressed in decibels and increases with length and frequency.
2. Why does higher frequency increase attenuation?
Higher frequencies create greater conductor and dielectric losses. Skin effect also pushes current toward the conductor surface, raising effective resistance.
3. Do connectors matter in total loss?
Yes. Every connector, coupler, or splice adds insertion loss. Small connector losses can become significant when multiple terminations appear in one run.
4. Can I use custom attenuation data?
Yes. Choose Custom and enter the measured or datasheet reference loss, reference frequency, and exponent that best matches the cable family.
5. Is the calculated max length exact?
No. It is a planning estimate based on your target loss and model inputs. Real installations should be verified with datasheets and field measurements.
6. Should I use 50 ohm or 75 ohm settings?
Use the impedance that matches your system and cable family. RF communication systems often use 50 ohm, while video and broadband commonly use 75 ohm.
7. How can I reduce signal loss?
Use shorter runs, lower-loss cable, fewer connectors, cleaner terminations, and suitable operating frequencies. Better routing and installation quality also help.