The Bible doesn't specify a certain age.
But those raging hormones hit before 25, and if marriage is an anecdote to reduce fornication, then waiting till 25 is disadvantageous.
Statistically, I hear couples who marry young are more likely to divorce. But other factors like regular church attendance for example correspond with lower divorce rates. I wonder what the divorce rate is for couples who marry young, but are really devout in their faith and hold to certain values that do not allow for affairs or divorce.
For younger marriages, they might be well prepared if both know and embrace their Biblical role in marriage--if both embrace a Biblical view of marriage and are devoted to abstaining from adultery, porn use, etc., if the husband is very serious about loving his wife as Christ loved the church, and honoring her, and the wife is very devoted to submitting to her husband and reverencing him. If they both go into it seeking to obey Biblical teachings on defrauding one another, that can help. Also, if they had some tutelage and guidance from their parents in selecting a mate, assuming parents are godly and wise, that could greatly help. If they had a community around them giving them godly advise after marriage, that could help also. There is an economic issue of the cost of living and the low income levels many have at the younger ages. Dad doesn't usually set them up with some land for a family farm in this day and age. The dominant culture in the US doesn't really align very well with some of these things.