Convert prefixes to masks and ranges without guesswork. Check hosts, wildcard values, and binary bits. Analyze IPv4 networks quickly with exports, examples, and charts.
| IPv4 Address | Input | Subnet Mask | Network | Broadcast | Usable Hosts |
|---|---|---|---|---|---|
| 192.168.10.14 | /24 | 255.255.255.0 | 192.168.10.0 | 192.168.10.255 | 254 |
| 10.0.5.130 | /26 | 255.255.255.192 | 10.0.5.128 | 10.0.5.191 | 62 |
| 172.16.8.200 | 255.255.248.0 | 255.255.248.0 | 172.16.8.0 | 172.16.15.255 | 2046 |
Prefix length equals the count of binary ones in the subnet mask. A /24 mask contains twenty-four leading ones and eight trailing zeros.
Subnet mask conversion uses contiguous binary bits. The dotted decimal mask comes from grouping the thirty-two bits into four octets.
Total addresses = 2^(32 - prefix). Conventional usable hosts = total addresses - 2. The common exceptions are /31 point-to-point links and /32 host routes.
Wildcard mask = 255.255.255.255 - subnet mask. Network address = IPv4 address AND subnet mask. Broadcast address = network address OR wildcard mask.
This subnet mask prefix length calculator helps network planning, VLAN sizing, IPv4 troubleshooting, address allocation, and CIDR verification. You can convert masks and prefixes in either direction, inspect binary values, review host capacity, and export the result table for documentation. The optional IPv4 field extends the calculation into network address, broadcast address, and usable host range analysis.
The classful comparison is useful for learning and auditing older documentation. The required host option can support quick design choices before a network change. Reserved IP tracking helps estimate effective usable capacity after infrastructure assignments. The chart gives a fast visual summary of address scale, usable count, and remaining effective capacity after reservations.
Prefix length is the number of leading one bits in a subnet mask. It defines how much of an IPv4 address belongs to the network portion.
A /27 uses twenty-seven network bits. Its dotted decimal subnet mask is 255.255.255.224.
A /24 contains 256 total addresses. In common subnetting practice, one network address and one broadcast address are not assigned to hosts.
A wildcard mask is the inverse of the subnet mask. It is often used in routing, access control lists, and matching address ranges.
Yes. You can still convert prefix length and subnet mask, see binary values, and review host capacity. Network and broadcast results need an IPv4 address.
A /31 can be used on point-to-point links. A /32 identifies one host route. These cases do not follow the usual host subtraction rule.
Effective usable hosts equals conventional usable hosts minus any custom reserved IPs you entered. It estimates practical capacity after internal assignments.
Use it during planning. Enter your required usable host count to find the smallest subnet that can support that demand.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.