CIDR Calculator
Find the smallest CIDR block that fits N hosts. Plan IP allocations efficiently.
| Smallest CIDR fitting 50 hosts | /26 |
| Total addresses in /26 | 64 |
| Usable hosts | 62 |
| Address space wasted | 12 |
What is CIDR Calculator?
When planning a network, you start with a host count and work backwards to a CIDR prefix. Subnetting requires powers of 2 — fitting 50 hosts needs at least 64 addresses (2 reserved for network/broadcast), which is a /26. This tool calculates the smallest CIDR that satisfies your host count.
Frequently asked questions
Why subtract 2?▼
Every IPv4 subnet reserves the first address (network) and last address (broadcast). Only the addresses in between can be assigned to hosts.
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