Tools / nr-link-budget-calculator

5G NR Link Budget Calculator

Calculate 5G NR downlink and uplink link budget, receiver sensitivity, received power, link margin, and maximum cell range using the latest 3GPP NR channel model basis from TR 38.901 Release 18.

Scenario and Channel

Propagation Model

LOS / NLOS

Terminal Environment

Center Frequency (GHz)

Channel Bandwidth (MHz)

Subcarrier Spacing (kHz)

Allocated PRBs

Current 2D Distance (m)

gNB Antenna Height (m)

UE Antenna Height (m)

For RMa, building height and street width are explicit model inputs. They are not the same as gNB antenna height. This avoids the ambiguity seen in some public calculators.

Power, Antenna, and Receiver Inputs

gNB Total TX Power (dBm)

gNB Antenna Gain (dBi)

gNB Feeder / RF Loss (dB)

gNB Noise Figure (dB)

UE Total TX Power (dBm)

UE Antenna Gain (dBi)

UE Body / Device Loss (dB)

UE Noise Figure (dB)

Required DL SINR (dB)

Required UL SINR (dB)

TX power is treated as total scheduled carrier power. The tool derives allocated power from the PRB share, which fixes the public-calculator issue where only 12 subcarriers were effectively used in the power split.

Losses and Margins

Exterior Wall / Penetration Loss (dB)

Indoor Depth (m)

Indoor Attenuation (dB/m)

Foliage Loss (dB)

Rain / Ice Margin (dB)

Interference Margin (dB)

Shadow / Fade Margin (dB)

Configure the scenario and calculate.

Summary

Path Loss at Current Distance -

Effective Additional Losses -

DL Max Range -

UL Max Range -

Cell Range Limit -

Limiting Direction -

Downlink and Uplink Result

Metric	Downlink	Uplink
No calculation yet.

How to Use This Tool

Select the propagation model and whether you want a LOS or NLOS path-loss calculation.
Enter the carrier frequency, bandwidth, SCS, and the allocated PRBs used by the channel you are budgeting.
Provide the current 2D distance plus gNB and UE antenna heights.
For RMa, enter street width and average building height. Those are mandatory RMa model inputs.
If the terminal is indoors behind an external wall, select Indoor (O2I) and fill in wall loss, indoor depth, and indoor attenuation. For pure indoor-office modeling, use InH.
Enter TX power, gains, losses, receiver noise figures, and required SINR for both DL and UL.
Press Calculate Link Budget to see current received level, sensitivity, margin, and the maximum supported DL/UL range. The final cell range is the lower of the two directions.

Notes and Fixes

Latest spec basis: path loss models use TR 38.901 Release 18.1.0, clause 7.4.1, not older Release 15-era snapshots.
RMa LOS breakpoint: the piecewise RMa LOS implementation uses the correct breakpoint handling for d2D > dBP, which addresses a problem reported in the reference calculator comments.
Antenna height impact: gNB and UE heights are used directly in d3D and breakpoint calculations, so changing heights changes the result where the model requires it.
Power allocation fix: transmit power is distributed over the actual scheduled PRB share of the carrier instead of implicitly treating the allocation as a fixed single RB / 12-subcarrier case.
Indoor clarity: O2I penetration is modeled explicitly as wall loss + indoor depth × indoor attenuation. It is separate from indoor-only InH path loss.
Range output: the tool gives both DL and UL max range and the final range-limiting direction, which was also requested in the reference comments.