EIRP Calculator for Construction Radio Systems

Plan temporary networks across large construction zones. Enter transmitter power, gains, and pathway losses easily. Get clear EIRP, watts, and compliance flags instantly here.

Calculator Inputs

Use realistic pathway losses for accurate field estimates.

Enter numeric power.
Converted internally to dBm.
Set 0 if none.
Typical small whip: 2-5 dBi.
Total RF cable run.
Depends on cable and frequency.
Includes adapters, surge protectors.
Typical 0.1-0.3 dB each.
Set 0 if none.
Example: ~3.5 dB for 2-way.
Lightning arrestor, filters, aging.
Used for documentation and checks.
Change to local project requirement.
Compare EIRP against your entered limit.

Example Data Table

Scenario Tx Power Ant Gain Cable (m) Losses Total EIRP (dBm)
Site radio, short run 1 W 5 dBi 20 3.3 dB 31.7
High mast, longer cable 2 W 8 dBi 45 8.6 dB 32.4
Splitter feed, two zones 1 W 6 dBi 30 7.1 dB 28.9

Numbers above are illustrative for planning and documentation.

Formula Used

EIRP is calculated using decibel addition for gains and losses:

  • Tx(dBm) is converted from W, mW, dBm, or dBW.
  • TotalLoss(dB) = CableLoss + ConnectorLoss + SplitterLoss + MiscLoss.
  • EIRP(dBm) = Tx(dBm) + AmpGain(dB) - TotalLoss(dB) + AntGain(dBi).

Watt conversion: W = 10^((dBm - 30)/10).

How to Use This Calculator

  1. Enter the transmitter power and choose its unit.
  2. Add any inline amplifier gain before the antenna.
  3. Enter antenna gain and estimate pathway losses.
  4. Include cable length and loss per meter.
  5. Count connectors, splitters, and other losses.
  6. Set an EIRP limit if compliance matters.
  7. Press Submit to view results above the form.

Notes for Construction Use

  • Long temporary cable runs can erase antenna gains quickly.
  • Keep connectors clean; small losses add up.
  • Document frequency and hardware per site safety policy.
  • Use CSV or PDF exports for handover reports.

Radio link planning for active sites

Construction projects rely on temporary radios, telemetry gateways, and wireless controls that must cover changing work zones. This calculator estimates effective isotropic radiated power by combining transmitter output, optional inline gain, and antenna gain, then subtracting pathway losses. The result helps you choose safe equipment settings, compare antenna options, and communicate expected coverage to supervisors.

Input data that improves accuracy

Use manufacturer datasheets for antenna gain and cable attenuation at the operating frequency. Measure cable length along actual routing, including slack and service loops. Count every connector, adapter, lightning arrestor, and bulkhead. Enter splitters only when one transmitter feeds multiple antennas. Keep miscellaneous losses for filters, aging, moisture, and bend radius effects.

Loss modeling and what it reveals

Because decibels add linearly, small losses quickly reduce radiated power. A long cable run can cancel a high gain antenna, and several connectors can erase the benefit of an amplifier. Reviewing the loss breakdown helps field teams shorten runs, move hardware closer to the antenna, or select lower loss coax to recover margin.

Compliance and documentation workflow

Many projects include limits based on local rules, shared spectrum policies, or client standards. By entering a limit, the tool reports a pass or fail status and the remaining margin in decibels. Export the calculation to CSV for logs or to PDF for handover packages, commissioning checklists, and safety reviews.

Practical optimization steps

Start with conservative power, then adjust using the margin result. Reduce loss before increasing power: shorten cable runs, minimize connectors, and avoid unnecessary splitters. If coverage is weak, consider relocating antennas higher and away from steel obstructions, then recompute. Recheck after equipment changes or when site layouts shift during phases.

For multi-tenant sites, coordinate channel plans and keep a record of antenna types, heights, and orientations. When using portable masts, note wind loading and secure anchoring. Consistent documentation reduces troubleshooting time and supports repeatable setups across crews and subcontractors during routine weekly inspections and shift handovers.

FAQs

What does EIRP represent on a construction site?

EIRP estimates how strong your signal appears if it radiated equally in all directions. It combines transmitter output, antenna gain, and pathway losses, so crews can compare setups and document expected coverage.

Why does cable loss matter so much?

Cable attenuation increases with length and frequency. Even a few decibels can halve radiated power. Shorter runs, lower-loss coax, and fewer bends often improve performance more than raising transmitter power.

Should I enter antenna gain in dBi or dBd?

Use dBi when possible, because it matches the calculator input. If you only have dBd, add 2.15 dB to convert to dBi before entering it.

How do I estimate connector and splitter losses?

Use typical values from datasheets or standards: many connectors are 0.1–0.3 dB each. Splitters vary by type, but a two-way splitter is often around 3–4 dB plus connector losses.

What if my result fails the limit check?

First reduce losses: shorten cable, remove splitters, or replace damaged connectors. Then reassess antenna gain and amplifier settings. Only increase transmitter power if rules allow and margins remain negative.

Can I use the exports for commissioning reports?

Yes. Export CSV for calculations logs and trend checks, or export PDF for handover packs. Include frequency, equipment model numbers, antenna height, and any assumptions so the next crew can reproduce the setup.

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Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.