Researchers looked at transcripts and data of more than 18,000 tenth grade students, in a study carried out to find what difference extra study at home makes.
They found homework doesn't necessarily help children to get more grades, but may help them achieve better standardised test scores, the 'Daily Mail' reported.
The findings by researchers from the University of Virginia in Charlottesville, US, show more homework assignments didn't translate into better grades.
"The more time students spend on homework, it's not clear that they are getting better grades or better test scores," co-author of the study Robert Tai, said.
"What we are concerned with is that homework is just being assigned rather than being used to integrate what's going on in the classroom.
The study isn't suggesting all homework is bad, especially when it comes to maths.
"When it comes to math, what we found is that there is a bit of a sweet spot," Tai said.
Tai said that students who spend about a half an hour on maths homework reported that their grades and test scores were actually better.
Researchers believe the study comes as a wake up call for educators, the report said.
"Teachers need to be much more clear about why they are assigning homework and what the homework is for.
"If teachers aren't really incorporating homework into their teaching, it's unclear there is any type of benefit at all and it actually may end up hurting students," he said.
The study points to factors like class participation and attendance as better indicators of students