From Longman Dictionary of Contemporary Englishmay/might/could (just) as wellmay/might/could (just) as wella) informalSUGGEST used when you do not particularly want to do something but you decide you should do it I suppose we may as well get started. b) INSTEADused to mean that another course of action would have an equally good result The taxi was so slow we might just as well have gone on the bus. → well
Examples from the Corpus
may/might/could (just) as well• It might as well be now.• I thought I might just as well come down to the point.• Besides, they cost so much, you might as well get some fun out of them.• And we might as well get used to it and resolve to cope.• While she was there, they might as well have added the charge of breaching the Trades Description Act.• And if you have to plough the field anyway, you might as well plant it at the same time.• She might as well see how the enemy behaved themselves in a place like this.• If the traveler expects the high way to be safe and well-graded, he might as well stay at home. 