| Cover Page | Dec. 02, 2020 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | Dec. 2, 2020 |
| 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 |
