You have to use the formula
![F=ma](https://img.qammunity.org/2021/formulas/physics/college/kxqi3lxi3fjfv761qhdu0s1p00agxd9vve.png)
Where F is the foce, m is the mass and a is the acceleration. In this case, the force you're interested in is the weight force, and the acceleration is the one due to gravity. So, the formula becomes
![F=mg](https://img.qammunity.org/2021/formulas/physics/middle-school/rcrgo07k7a6rjryhi8k5pstkr9aa31xtgi.png)
Plug the values for m and g and you'll get the weight.