Spread factor VS payload size on LoRa

Differences Between North America & Europe

In essence, longer range is possible in Europe because of a higher permissible spreading factor. However, data throughput is generally higher in North America because of Europe’s duty cycle restriction, but keep in mind that using the highest spreading factor for North America (10) limits payload size to 11 bytes. Whereas in Europe the payload can be 51 bytes at the highest spreading factor (12).

Region	North America	Europe
ISM Band	902-928 MHz	863-870 MHz
Regulated by	FCC	ETSI
TX Restriction	400ms tx time	Generally 1% tx duty-cycle
Payload sizes	11 – 242 bytes	51 – 242 bytes
Spreading factors	7 – 10	7 – 12
Data rates	1 – 12.5 kbps	0.3 – 5.5 kbps
Max transmit power	21 dBm	Generally 14 dBm

Spreading Factor & Bandwidth	Transmit Data rate	Maximum Payload Size
		North America	Europe
SF_8 500kHz(AT+SENDH)	12.5 kbps	242 bytes	-
SF_7 125kHz	5.47 kbps	242 bytes	242 bytes
SF_8 125kHz	3.125 kbps	129 bytes	242 bytes
SF_9 125kHz	1.76 kbps	53 bytes	115 bytes
SF_10 125kHz	0.98 kbps	11 bytes	51 bytes
SF_11 125kHz	0.44 kbps	-	51 bytes
SF_12 125kHz	0.25 kbps	-	51 bytes

NOTE: the effective throughput data rate in Europe is generally the transmit data rate divided by 10 after accounting for the duty cycle limitations. Therefore, throughput with SF_12 will be around 25 bps.