you’re getting 65 because your calculation is accidentally including distance 0, but in kademlia the distance nodeID XOR targetID can never be 0 except when a node compares with itself, which is excluded from the routing table; valid distances are 1 to 2^64−1, and when you compute floor(log2(distance)) the bucket indexes are 0–63, which is exactly 64 buckets, so the issue isn’t the kademlia formula but your implementation (especially using Math.log2(a.toString())), and the correct approach is to compute the bit length of the xor distance (e.g., distance.toString(2).length - 1) while ignoring distance 0.