Cover Page
| Cover Page | Sep. 01, 2021 | Dec. 02, 2020 |
| Cover [Abstract] | ||
| Document Type | 8-K | |
| Document Period End Date | Sep. 1, 2021 | |
| Entity Registrant Name | FIVE BELOW, INC. | |
| Entity Incorporation, State or Country Code | PA | |
| Entity File Number | 001-35600 | |
| Entity Tax Identification Number | 75-3000378 | |
| Entity Address, Address Line One | 701 Market Street | |
| Entity Address, Address Line Two | Suite 300 | |
| Entity Address, City or Town | Philadelphia | |
| Entity Address, State or Province | PA | |
| Entity Address, Postal Zip Code | 19106 | |
| City Area Code | 215 | |
| Local Phone Number | 546-7909 | |
| Written Communications | false | |
| Soliciting Material | false | |
| Pre-commencement Tender Offer | false | |
| Pre-commencement Issuer Tender Offer | false | |
| Entity Emerging Growth Company | false | |
| Entity Central Index Key | 0001177609 | |
| Amendment Flag | false |