IPv4 IP Range Calculator
Enter an IPv4 address and CIDR prefix to calculate the network range, usable host range, subnet mask, broadcast address, and more.
What is an IP range calculator?
An IP range calculator helps you translate an IP address and subnet notation into practical network details. Instead of manually doing binary math, you can instantly see:
- Network address
- Broadcast address
- First and last usable host
- Total addresses and usable hosts
- Subnet mask and wildcard mask
This is useful for system administrators, cloud engineers, IT students, and anyone designing or troubleshooting network segmentation.
How CIDR and subnetting determine an IP range
1) The IP address
IPv4 addresses are 32 bits long and written in dotted decimal format (for example, 10.0.5.34).
2) The prefix length
The prefix (like /24) tells you how many bits belong to the network portion. The remaining bits are host bits.
3) Network and broadcast boundaries
When you apply the subnet mask to the IP, you find the network address. The highest address in that same block is the broadcast address. Everything in between is the potential host range.
How to use this calculator
- Enter an IPv4 address (example:
172.16.2.88). - Enter the CIDR prefix (example:
20). - Click Calculate Range.
- Review network details and host boundaries in the results table.
The calculator also handles important special cases such as /31 and /32 networks.
CIDR quick reference
| CIDR | Subnet Mask | Total Addresses | Typical Usable Hosts |
|---|---|---|---|
| /32 | 255.255.255.255 | 1 | 1 (single host route) |
| /30 | 255.255.255.252 | 4 | 2 |
| /29 | 255.255.255.248 | 8 | 6 |
| /24 | 255.255.255.0 | 256 | 254 |
| /16 | 255.255.0.0 | 65,536 | 65,534 |
Common mistakes this tool helps you avoid
Assuming every subnet has 254 hosts
That is only true for /24. Different prefixes produce very different host capacities.
Misidentifying the broadcast address
If the broadcast address is wrong, devices can fall outside expected boundaries and routing can fail.
Ignoring /31 and /32 behavior
/31 networks are commonly used for point-to-point links, and /32 represents a single host route.
Practical examples
Office VLAN planning
If you need 60 devices in a department VLAN, this calculator quickly shows that /26 (64 total addresses, 62 usable) is a strong fit.
Cloud network design
When carving a VPC or virtual network into subnets, precise IP ranges prevent overlap and simplify route table management.
Troubleshooting DHCP scope issues
If DHCP hands out addresses outside expected limits, comparing configured scopes with calculated boundaries reveals mismatches fast.
Final thoughts
Subnetting is foundational in networking. A reliable IP range calculator reduces error, saves time, and helps you validate design decisions with confidence. Use the calculator above whenever you need quick, accurate CIDR range results.