Calvin's rhymes with:
avon's, beethoven's, bevans, bevens, bivens, blevens, craven's, cravens, devens, divens, donovan's, donvan's, eleven's, elevens, enlivens, evans, evans', evens, givens, havens, heaven's, heavens, hillhaven's, ivens, leavens, levens, maven's, mavens, nivens, nonwovens, ovens, ravens, sarajevan's, sarajevans, scrivens, seven's, sevens, slavens, stephen's, stephens, steven's, stevens, stevens', sullivan's, sullivans
Calvin's sounds like:
calving, chelyabinsk, clapping, clipping, clippings, clubbing, colebank