Hi

[Rafi_nabil]

does spotify use's data alot? Without premium

[MrDavo]

Hi,

The data size will depend on the quality, Spotify offers low, high and extreme sound quality settings. The normal setting is 96 kbps, the high is 160 kbps and extreme is 320kbps.

Quote from

https://community.spotify.com/t5/Help-iOS-iPhone-iPad/Data-Usage/td-p/502830 

I found a great chart from a previous post which you can work with your data plan. 

Quality 96 kbps => 0.72 MB per minute. (Only in Mobile these days)
Quality 160 kbps => 1.2 MB per minute. (Free, Unlimited, Premium)
Quality 320 kbps => 2.4 MB per minute. (Only Premium at Desktop, mobile streaming some devices)