v3.10.0.1
Document and Entity Information - USD ($)
12 Months Ended
Apr. 30, 2018
Jul. 16, 2018
Oct. 31, 2017
Document And Entity Information [Abstract]      
Document Type 10-K    
Amendment Flag false    
Document Period End Date Apr. 30, 2018    
Document Fiscal Year Focus 2018    
Document Fiscal Period Focus FY    
Trading Symbol KALV    
Entity Registrant Name KALVISTA PHARMACEUTICALS, INC.    
Entity Central Index Key 0001348911    
Current Fiscal Year End Date --04-30    
Entity Well-known Seasoned Issuer No    
Entity Current Reporting Status Yes    
Entity Voluntary Filers No    
Entity Filer Category Non-accelerated Filer    
Entity Common Stock, Shares Outstanding   10,799,895  
Entity Public Float     $ 60,287,969