| Cover | Sep. 29, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Sep. 29, 2021 |
| Entity File Number | 000-23248 |
| Entity Registrant Name | SIGMATRON INTERNATIONAL, INC. |
| Entity Central Index Key | 0000915358 |
| Entity Tax Identification Number | 36-3918470 |
| Entity Incorporation, State or Country Code | DE |
| Entity Address, Address Line One | 2201 Landmeier Road |
| Entity Address, City or Town | Elk Grove Village |
| Entity Address, State or Province | IL |
| Entity Address, Postal Zip Code | 60007 |
| City Area Code | 847 |
| Local Phone Number | 956-8000 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock $0.01 par value per share |
| Trading Symbol | SGMA |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
