index out of range with length as for loop param

I am trying to loop through some inputs that are given to the function as an array of floats. I use a for loop to do so with the length of the array as the parameter. I don't know how but it seems that the index still somehow gets out of bounds...

 using UnityEngine;
 using System.Collections;
 
 public class Neuron {
     public float[] weights=new float[100];
     
     public float calculate(float[] inputs){
             float activation = 0f;
             for(int i=0;i<inputs.Length;i++){
                 activation+=inputs[i]*weights[i];
             }
             //bias
             activation += -1 * weights [weights.Length - 1];
             //Sigmoid
             return (1 / (1 + Mathf.Exp(-activation/0.5f)));
     }
     public void setWeights(float[] wts){
         weights = wts;
         Debug.Log(wts.Length);
     }
 }
 

With the error:

 IndexOutOfRangeException: Array index is out of range.
 Neuron.calculate (System.Single[] inputs) (at Assets/Neuron.cs:12)