EARFCN / NR-ARFCN Calculator
Convert between channel number and frequency — LTE EARFCN (per band, DL & UL) and 5G NR-ARFCN (global raster), both directions, live.
Convert between channel numbers and carrier frequencies, live. The first tool does LTE EARFCN (per band, with the paired uplink); the second does 5G NR-ARFCN on the global frequency raster. Type in either box and the conversion updates instantly.
LTE EARFCN Calculator
Enter a downlink EARFCN to get its frequency and the paired uplink EARFCN/frequency for that band; or enter a frequency to get the nearest EARFCN. TDD bands share one channel number for DL and UL.
5G NR-ARFCN Calculator
NR-ARFCN is a single global numbering of 5 kHz points across 0–100 GHz; no band is needed to convert.
How EARFCN Works
An EARFCN (E-UTRA Absolute Radio Frequency Channel Number) names a 100 kHz channel raster point. Each LTE band defines a lower edge frequency and an EARFCN offset, and the frequency is a linear function of the channel number:
The 0.1 is the 100 kHz raster in MHz. For an FDD band the uplink uses its own F_UL_low/N_Offs-UL, so the paired UL EARFCN differs from the DL one by a fixed band offset; for a TDD band there is a single carrier, so DL and UL share the same EARFCN and frequency. This tool carries the per-band constants for the common bands (1, 2, 3, 4, 5, 7, 8, 12, 13, 20, 25, 28, 66, 71 FDD and 38, 40, 41 TDD).
| Band (example) | DL range (MHz) | Duplex |
|---|---|---|
| Band 3 | 1805–1880 | FDD |
| Band 7 | 2620–2690 | FDD |
| Band 20 | 791–821 | FDD |
| Band 41 | 2496–2690 | TDD |
How NR-ARFCN Works
5G replaces the per-band EARFCN with a single global raster. The frequency is:
with three ranges of global raster step ΔF_Global:
| Frequency range | ΔFGlobal | FREF-Offs | NREF range |
|---|---|---|---|
| 0 – 3000 MHz | 5 kHz | 0 MHz | 0 – 599999 |
| 3000 – 24250 MHz | 15 kHz | 3000 MHz | 600000 – 2016666 |
| 24250 – 100000 MHz | 60 kHz | 24250.08 MHz | 2016667 – 3279165 |
Note this is the channel raster; the SSB has its own coarser raster (the GSCN / synchronization raster) used only for cell search.
Q. Why does the LTE calculator need a band but the NR one doesn't?
A. EARFCN is defined per band — the same channel number means different frequencies in different bands, because each band carries its own lower-edge frequency and offset. NR-ARFCN is a single global mapping from number to frequency, so it stands alone.
Q. What's the difference between NR-ARFCN and GSCN?
A. NR-ARFCN is the fine channel raster (down to 5 kHz) used to place any carrier. GSCN (the synchronization raster) is a much coarser set of points where an SSB may sit, so a UE searching for a cell only checks a handful of frequencies instead of every ARFCN.
Q. For an FDD band, how far apart are the DL and UL EARFCNs?
A. By a fixed per-band offset equal to the difference of the two bands' EARFCN offsets (N_Offs-UL − N_Offs-DL) — the tool computes the paired UL EARFCN for you when you enter the DL one.
Related
Frequency and channel numbering connect to spectrum and cell search.