Carmedin
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Subnet / CIDR
Calculator.
Work out network address, broadcast, usable host range, and subnet splits from any IPv4 address and CIDR prefix or subnet mask — instantly, entirely in your browser.
⌁Processed locally
/24CIDR + subnet masks
01Binary view
Calculate a subnet
IPv4 · client-side only
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IPv4 inputCIDR prefix or subnet mask
If the IP field already contains /CIDR, that prefix is used. Otherwise enter a subnet mask here.
Everything runs client-side in your browser. Nothing you enter is sent to any server.
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No calculation yetEnter an IPv4 address and CIDR prefix or subnet mask to see network details, host range, split options, and binary representation.
Reference
Common Subnet Masks
CIDR prefix, subnet mask, total addresses, and usable-host counts for common IPv4 ranges.
| CIDR | Subnet Mask | Total Addresses | Usable Hosts |
|---|---|---|---|
| /8 | 255.0.0.0 | 16,777,216 | 16,777,214 |
| /16 | 255.255.0.0 | 65,536 | 65,534 |
| /24 | 255.255.255.0 | 256 | 254 |
| /25 | 255.255.255.128 | 128 | 126 |
| /26 | 255.255.255.192 | 64 | 62 |
| /27 | 255.255.255.224 | 32 | 30 |
| /28 | 255.255.255.240 | 16 | 14 |
| /29 | 255.255.255.248 | 8 | 6 |
| /30 | 255.255.255.252 | 4 | 2 |
| /31 | 255.255.255.254 | 2 | 2 (RFC 3021 P2P) |
| /32 | 255.255.255.255 | 1 | 1 (host route) |
Need more than a number on a page?
We design and manage the networks behind the addressing.
Subnetting is one piece of a larger network design. From VLAN segmentation to firewall policy, that's what we do.