RF Spectrum Regulations

Any device that intentionally radiates radio frequency (RF) energy is subject to regulation in every jurisdiction it is sold or operated in. The regulatory bodies define which frequency bands are available for what purposes, the maximum transmit power, the modulation requirements, and various other rules a device must follow before it can be legally marketed.

This page is intended as a central reference for the most commonly-cited limits. The band-specific pages on this site (e.g. Sub-GHz ISM Bands) link here rather than duplicating the full tables.

Caution

This page is a summary. Always consult the authoritative regulation (FCC Part 15, EN 300 220, AS/NZS 4268, etc.) and any regional certification body before designing a product for sale. Numbers here may be outdated or simplified.

Regulatory Bodies

Different jurisdictions have different regulatory authorities. The most commonly encountered are:

Region	Authority	Key Standards / Rules
United States	FCC (Federal Communications Commission)	FCC Part 15 (especially 15.231, 15.247, 15.249)
European Union	National authorities under ETSI harmonised standards	RED (Radio Equipment Directive 2014/53/EU), EN 300 220 (sub-GHz), EN 300 328 (2.4 GHz), EN 301 893 (5 GHz)
United Kingdom	Ofcom	IR 2030 Interface Requirement (mirrors the EU harmonised standards post-Brexit)
Australia	ACMA (Australian Communications and Media Authority)	Radiocommunications (Low Interference Potential Devices — “LIPD”) Class Licence, AS/NZS 4268
New Zealand	RSM (Radio Spectrum Management, Ministry of Business, Innovation and Employment)	General User Radio Licence (GURL) — Short Range Devices, AS/NZS 4268
Canada	ISED (Innovation, Science and Economic Development Canada)	RSS-210, RSS-247
Japan	MIC (Ministry of Internal Affairs and Communications)	ARIB STD-T108 (920 MHz band), ARIB STD-T66 (2.4 GHz), Radio Law Article 4

Key Terms

• EIRP (Equivalent Isotropically Radiated Power) — the power that an isotropic antenna would need to radiate to produce the peak power density of the actual transmitter + antenna combination. EIRP = P_conducted × G_antenna (or in dB: EIRP_dBm = P_dBm + G_dBi). Most modern regulations specify EIRP rather than conducted power.
• ERP (Effective Radiated Power) — older term, referenced to a half-wave dipole instead of an isotropic radiator. ERP = EIRP − 2.15 dB.
• Conducted power — the RF power measured at the transmitter output port, before the antenna. FCC Part 15 often specifies conducted power separately from the maximum antenna gain.
• Duty cycle — the fraction of time a transmitter may be on the air during a fixed observation window (typically 1 hour). Heavily used in EU regulations for sub-GHz bands.
• LBT (Listen Before Talk) — the transmitter must verify the channel is clear before transmitting. Often an alternative to duty cycle restrictions.
• AFA (Adaptive Frequency Agility) — the transmitter must hop between channels to share the spectrum (used by 2.4 GHz Bluetooth/Wi-Fi co-existence rules).
• FHSS (Frequency-Hopping Spread Spectrum) and DSSS (Direct-Sequence Spread Spectrum) — modulation styles that some regulatory regimes treat as a category, sometimes with relaxed power limits (e.g. FCC Part 15.247).

EIRP Compliance Map

Enter your transmitter conducted power and antenna gain below, then pick a protocol (or specify a custom frequency). The map will colour each regulatory region green if your EIRP is within the legal limit, or red if it exceeds it. Grey regions are not allocated for unlicensed use of the chosen band; the regions in light grey are outside the scope of this page.

Transmitter power: 10 dBm (10.00 mW)Antenna gain: 2.0 dBi

EIRP =12.0 dBm(15.8 mW)

Band: 2.4 GHz ISM (2400 – 2483.5 MHz)

Compliant Exceeds limit Not allocated Outside scope of this page

Region	Limit	Status	Margin
United States	36 dBm	OK	+24.0 dB
Canada	36 dBm	OK	+24.0 dB
European Union	20 dBm	OK	+8.0 dB
United Kingdom	20 dBm	OK	+8.0 dB
Australia	36 dBm	OK	+24.0 dB
New Zealand	36 dBm	OK	+24.0 dB
Japan	20 dBm	OK	+8.0 dB

Caution

The widget uses each region’s FHSS / spread-spectrum EIRP allowance (which is what every built-in protocol — Wi-Fi, Bluetooth, BLE, ZigBee, LoRa — qualifies for). Narrowband or non-frequency-hopping modulations may be capped lower in some regions (e.g. NZ 2.4 GHz drops from 36 dBm to 30 dBm for non-FHSS digital modulation, and some EU sub-bands have lower limits for narrowband). Note also that a green region only means the regulatory EIRP ceiling is met under the most permissive conditions for that band — your specific stack may not qualify. The most common gotcha: EN 300 328 only allows +20 dBm in the EU when the device implements “adaptivity” (frequency hopping across ≥ 15 channels + collision avoidance); non-adaptive equipment is capped at +10 dBm.¹ Always cross-check the chip / module’s regional certifications.

Summary Table

The table below consolidates the headline limits for each (band, region) combination. The per-band sections that follow give more detail and the exact sub-band breakdowns where applicable.

Caution

“Max EIRP” figures are the typical headline limit for the most common digital-modulation / spread-spectrum use case in each band. Many bands have sub-bands with different limits, and many regions have higher allowances for specific modulation schemes or LBT/DFS-compliant equipment. Always check the actual standard.

Band	Region	Max EIRP	Conditions	Notes
315 MHz	US	~−1 dBm (≈ 100 µV/m @ 3 m field strength)	“Periodic operation” only (FCC Part 15.231) — short bursts, no continuous Tx	Car key fobs, garage remotes
	EU / UK	Not allocated for unlicensed ISM use.
	AU	Not allocated for unlicensed ISM use.
	NZ	Not allocated for unlicensed ISM use.
	CA	Similar to US (RSS-210)	Periodic operation rules apply
	JP	Not allocated for unlicensed ISM use.
433 MHz (433.05 – 434.79 MHz)	EU	10 dBm (10 mW)	10% duty cycle	EN 300 220-2; sub-band rules apply
	UK	10 dBm	10% duty cycle	Ofcom IR 2030 mirrors EU
	US	Restrictive narrowband only	FCC Part 15.231/15.249 limits	Not an ISM band in US
	AU	14 dBm (25 mW)	—	LIPD Class Licence; 915 MHz preferred locally
	NZ	14 dBm (25 mW)	—	RSM GURL mirrors AU
	CA	Restrictive — similar to US.
	JP	Not allocated for unlicensed ISM use.
868 MHz (863 – 870 MHz)	EU	14 dBm (25 mW) in most sub-bands	1% duty cycle (most sub-bands)	EN 300 220-2; 27 dBm + 10% DC in 869.4–869.65 MHz; 7 dBm + 100% DC in 869.7–870 MHz
	UK	Same as EU	Same as EU	Ofcom IR 2030 mirrors EU
	US	Not available (overlaps with cellular allocations).
	CA	Not available.
	AU	Not available (overlaps with GSM-900 / LTE band 8).
	NZ	Not available.
	JP	Use the 920 MHz band (ARIB STD-T108) instead.
915 MHz (902 – 928 MHz)	US	36 dBm effective (1 W conducted into 6 dBi antenna)	FHSS or digital modulation (Part 15.247); higher antenna gain trades against conducted power	Primary “US ISM” sub-GHz band
	CA	Same as US	RSS-247
	AU	30 dBm (1 W EIRP) in 915 – 928 MHz	Digital modulation / spread spectrum	902–915 MHz allocated to other services locally
	NZ	30 dBm (1 W EIRP) in 921 – 928 MHz	Digital modulation / spread spectrum	Primary local sub-GHz IoT band
	JP	~24 dBm (250 mW) in 920 – 928 MHz	ARIB STD-T108, channel and LBT rules	Japanese sub-GHz IoT band
	EU	Not available (cellular allocations).
	UK	Not available.
2.4 GHz (2400 – 2483.5 MHz)	EU	20 dBm (100 mW)2	Same 20 dBm limit applies to both FHSS (Classic Bluetooth) and wideband (Wi-Fi, BLE 1M/2M PHY) modes; 10 dBm/MHz PSD cap; adaptive equipment requirements	Wi-Fi, Bluetooth, ZigBee. Not 10 dBm — that’s a chip-vendor SKU cert ceiling, not the regulatory limit
	UK	20 dBm	Same as EU
	US	~36 dBm typical Wi-Fi (1 W conducted)	FCC Part 15.247; antenna gain rules	Point-to-point links allow higher EIRP
	CA	Same as US	RSS-247
	AU	36 dBm (4 W EIRP)	Spread spectrum / digital modulation	LIPD Class Licence; more permissive than EU
	NZ	36 dBm FHSS / 30 dBm non-FHSS digital modulation	FHSS condition required for the 36 dBm allowance (covers Classic Bluetooth and BLE)	RSM GURL
	JP	10 dBm/MHz density limit	ARIB STD-T66, per-mode caps
5 GHz (U-NII)	US	23 – 36 dBm depending on sub-band	DFS required in U-NII-2; TPC; indoor-only restrictions in some sub-bands	U-NII-1/2A/2C/3/4 split (FCC Part 15 Subpart E)
	EU	23 dBm (200 mW) in 5150–5350 MHz; 30 dBm (1 W) in 5470–5725 MHz	5150–5350 indoor only; DFS + TPC in 5470–5725	EN 301 893
	UK	Same as EU	Same as EU
	AU	23 dBm (200 mW) in 5150–5350; up to 36 dBm (4 W EIRP) in 5725–5875 for outdoor point-to-point	Indoor-only / DFS rules per sub-band	LIPD Class Licence
	NZ	Mirrors AU	Mirrors AU	RSM GURL
	CA	Similar to US	RSS-247 / RSS-210
	JP	Different sub-band split	—	Consult Japanese authority for specifics

Band Summaries

315 MHz (Region 2)

Primarily used in North America and parts of Asia for car key fobs and short-range remote controls.

• US (FCC Part 15.231) — very low power, intermittent transmission only, restrictions on duty cycle. Typically used for “periodic operation” devices.
• Not generally available as an ISM band in EU.
• AU / NZ — not generally allocated for unlicensed ISM use; this band is used by other services.

433 MHz (Region 1 ISM)

The 433.05 - 434.79 MHz band.

• EU (EN 300 220) — typical EIRP limit of 10 dBm (10 mW), 10% duty cycle. There are several sub-bands with varying rules.
• US — not an ISM band per se; some narrowband operation possible under FCC Part 15.231 / 15.249 with restrictive limits.
• AU (ACMA LIPD Class Licence) — 433.05 - 434.79 MHz available for general-purpose telemetry and remote control up to ~25 mW EIRP. Devices used here are commonly imported but the 915 MHz band is preferred locally because of more available spectrum.
• NZ (RSM General User Radio Licence — Short Range Devices) — broadly mirrors the ACMA LIPD class licence with similar power limits. The limit is 14 dBm EIRP. In NZ, significantly more power (30/36 dBm) is allowed for the 915 MHz band.³

Pieces of still wire are commonly

868 MHz (Region 1)

The 863 - 870 MHz European sub-GHz band, split into several sub-bands by EN 300 220:

• Most sub-bands: 14 dBm EIRP (25 mW), 1% duty cycle.
• 869.4 - 869.65 MHz: 27 dBm EIRP (500 mW), 10% duty cycle.
• 869.7 - 870 MHz: 7 dBm EIRP (5 mW), 100% duty cycle.

Full sub-band breakdown is in EN 300 220-2.

• AU / NZ — not available for unlicensed sub-GHz operation; this part of the spectrum is allocated to other services (GSM-900 / LTE band 8 overlap).

915 MHz (Region 2)

915 MHz covers the 902 - 928 MHz band. This is the North American and Australasia counterpart to the EU 868 MHz.

• US (FCC Part 15.247) — for FHSS or digital modulation systems: up to 30 dBm (1 W) conducted with up to 6 dBi antenna gain (higher gain allowed if conducted power is reduced 1 dB for every dB over 6 dBi). EIRP cap effectively 36 dBm for most cases.
• AU (ACMA LIPD Class Licence) — 915 - 928 MHz sub-band is available for digital modulation / spread-spectrum devices at up to 1 W EIRP. This is the main “Australian LoRaWAN” / sub-GHz IoT band (AU915 / AU923 LoRa plans). The lower part of the band (902 - 915 MHz) is allocated to other services.
• NZ (RSM GURL — Short Range Devices) — 921 - 928 MHz is the most-used sub-band locally, with similar 1 W EIRP allowance for digital modulation. The full 915 - 928 MHz range is broadly available under the relevant GURL. 30 dBm is allowed for non FHSS devices, 36 dBm allowed for FHSS devices.³
• Not available in EU for unlicensed operation (overlaps with GSM-900 / LTE band 8).

2.4 GHz (Worldwide ISM)

The 2400 - 2483.5 MHz band — used by Wi-Fi, Bluetooth, ZigBee, and most consumer wireless.

• EU (EN 300 328) — 20 dBm EIRP (100 mW) for both FHSS equipment (e.g. Classic Bluetooth) and wideband modulation (e.g. Wi-Fi, BLE 1M / 2M PHY). The standard literally says “The RF output power for FHSS equipment shall be equal to or less than 20 dBm.” A 10 dBm/MHz spectral power density cap also applies. Critically, the +20 dBm allowance only applies to adaptive equipment (frequency hopping across ≥ 15 channels with collision avoidance / LBT); non-adaptive equipment is capped at +10 dBm EIRP.²¹
• US (FCC Part 15.247) — up to 30 dBm (1 W) conducted, plus antenna gain rules.
• JP (ARIB STD-T66) — 10 dBm/MHz spectrum power density limit, various per-mode caps.
• AU (ACMA LIPD Class Licence) — up to 36 dBm EIRP for spread-spectrum / digital-modulation devices in the full 2400 - 2483.5 MHz band, which is more permissive than EU.
• NZ (RSM GURL — General Conditions, Bands marked FHSS / digital modulation) — up to 36 dBm EIRP (6 dBW) for FHSS devices (which includes Classic Bluetooth and BLE under the relevant interpretation); 30 dBm for non-FHSS digital modulation. The 36 dBm allowance is subject to a specific FHSS condition in the GURL — devices without frequency-hopping fall under the lower limit.³

Caution

You’ll sometimes see claims online that EU Bluetooth is limited to +10 dBm, not +20 dBm. The actual rule under EN 300 328 is: +20 dBm EIRP is only available to devices that implement “adaptivity” — frequency hopping across at least 15 channels combined with collision avoidance (e.g. Listen-Before-Talk).¹ Devices that don’t implement adaptivity are capped at +10 dBm EIRP.

A consequence is that vendors who don’t implement adaptive FHSS in their BLE stacks default to +10 dBm in EU — Nordic Semiconductor’s own range-extender documentation shows ETSI (EU) capped at +10 dBm for 1 / 2 Mbps Bluetooth LE while FCC (US) is capped at +20 dBm.⁴ The nRF21540 front-end module saturates at +20 dBm output, so it’s the soft cap there too.

Note also that BLE Coded PHY (the long-range S=2 / S=8 modes) has a narrower occupied bandwidth than 1M / 2M PHY. Depending on the symbol rate and interpretation, it may not meet the wideband definition under EN 300 328 and could fall under a stricter narrowband limit. This is the most common real gotcha when designing for high-power long-range BLE in the EU.

5 GHz (Worldwide ISM/U-NII)

A more fragmented band, split into multiple sub-bands (U-NII-1 / 2A / 2C / 3 / 4) with different power limits and DFS (Dynamic Frequency Selection) requirements to avoid weather radar interference.

• US (FCC Part 15 Subpart E) — U-NII-1 through U-NII-4, with EIRP limits ranging from 250 mW to 4 W depending on sub-band and use case (indoor vs outdoor).
• EU (EN 301 893) — 5150 - 5350 MHz (indoor only, 200 mW EIRP), 5470 - 5725 MHz (1 W EIRP with DFS / TPC required).
• AU (ACMA LIPD Class Licence) — 5150 - 5350 MHz (indoor only, 200 mW EIRP), 5470 - 5725 MHz (with DFS), 5725 - 5875 MHz (up to 4 W EIRP for outdoor point-to-point links).
• NZ (RSM GURL) — broadly mirrors AU.

See Also

• Sub-GHz ISM Bands — uses of the 315 / 433 / 868 / 915 MHz bands.
• Antennas — gain, EIRP and antenna design considerations.
• Electromagnetic Compatibility (EMC) — the broader compliance framework.

Footnotes

1. Michael Spörk (2025, Feb 6). Boosting Bluetooth Range: Understanding TX Power Regulations in the EU & US. Dewine Labs. Retrieved 2026-05-22, from https://dewinelabs.com/boosting-bluetooth-range-understanding-tx-power-regulations-in-the-eu-us/. ↩ ↩² ↩³

2. ETSI (2019, Jul). EN 300 328 V2.2.2 — Wideband transmission systems; Data transmission equipment operating in the 2,4 GHz band; Harmonised Standard for access to radio spectrum [specification]. Retrieved 2026-05-22, from https://www.etsi.org/deliver/etsi_en/300300_300399/300328/02.02.02_60/en_300328v020202p.pdf. ↩ ↩²

3. New Zealand Gazette (2022, Aug 1). Radiocommunications Regulations (General User Radio Licence for Short Range Devices) Notice 2022 [notice]. Retrieved 2026-05-21, from https://gazette.govt.nz/notice/id/2022-go3100. ↩ ↩² ↩³

4. Nordic Semiconductor. Range Extenders — Maximum regulatory TX output power [product page]. Retrieved 2026-05-22, from https://www.nordicsemi.com/Products/Wireless/Range-extenders#txPowerLimits. ↩