If your Gross income is at least -

Single - $12,400 add $1,650 if age 65 or older
Married Filing Separately - $5
Married Filing Jointly - $24,800 add $1,300 for each spouse age 65 or older
Head of Household - $18,650 add $1,650 if age 65 or older

If the income is from self employment then $400.  If you are a dependent the rules are different...

Do I need to file a federal return this year?

https://ttlc.intuit.com/replies/3302274