It depends on what kind of receiver you have and its filter bandwiths.
Some scanners and other receivers will have three FM bandwidths:
NFM = 2.5 kHz deviation / 11-12.5 kHz bandwidth
FM = 5 kHz deviation / 16-25 kHz bandwidth
WFM = 75 kHz deviation / 180-200 kHz bandwith (only for FM broadcast band)
For amateur radio and land mobile radio:
Narrow = 2.5 kHz deviation / 11.2 kHz bandwidth
Wide = 5 kHz deviation / 16 kHz bandwidth
In the UK as far as I know all amateur radio FM on the 2m band (144-146 MHz) is narrow.
I don't know if 70 cm (430-440 MHz) is narrow or wide.