From Longman Dictionary of Contemporary EnglishI would thinkI would think (also I would have thought, I should think/I should have thought British English) used when you are saying that you believe something is probably true We’ll need about 10 bottles of wine, I should think. I would have thought it would be better to wait a while. → think
Examples from the Corpus
I would think• Three reasons, I would think.• It'll be cooler down by the lake, I would think.• Pretty heavily on fire, too, I would think.• This looks tough, I would think, and then immediately forget about it.• She would wear it for Chapel Anniversary, I would think, because that was a very special occasion in Baldersdale.• I loathe this country, I would think, No, I love it.• No less than three hours, I would think, perhaps as many as five or six.• I should think Sarah and Greg will be going to the party.• My head, I would agree with her. I would think she was right.• "Will you have finished work by 6.30?'' "Oh yes, I should think so.''• I would think that she would get tired of cleaning up the house every day.• Male speaker I would think they'd like it two to three days old with a reasonable bounce.