There is no real standard sizing, just keep in mind Smaller sprockets = higher top end speed but lower acceleration and Larger sprocket = low top speed but high acceleration so the size you want is totally dependant on what you require from the bike. eg. if you ride enduro then you probably want something in medium size range so to get decent acceleration but with a good top speed.
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There is no real standard sizing, just keep in mind Smaller sprockets = higher top end speed but lower acceleration and Larger sprocket = low top speed but high acceleration so the size you want is totally dependant on what you require from the bike. eg. if you ride enduro then you probably want something in medium size range so to get decent acceleration but with a good top speed.