IP Address Range Calculator
Calculate the first, last and total number of IPv4 addresses covered by a given network address and prefix length.
Your results
Calculation breakdown
- Total addresses
- 2^(32 − prefix)
- Usable addresses
- total − 2 (network and broadcast reserved)
Worked example
A 10.0.0.0/16 network spans from 10.0.0.0 to 10.0.255.255, a total of 65,536 addresses with 65,534 usable.
Assumptions
- Covers IPv4 only.
- Standard /8 to /30 rules; /31 and /32 are special cases not covered.
How this calculator works
Enter a network IPv4 address and CIDR prefix to see the full address range it covers, from the network address to the broadcast address, plus the total and usable address counts.
Frequently asked questions
What's the difference between this and the subnet calculator?
This tool focuses on the full address range and counts; the subnet calculator also shows the mask in dotted-decimal and binary form.
Can I use this for a /31 or /32?
Those special cases have no separate network/broadcast address; this calculator applies standard rules best suited to /8 through /30.
Is this for public or private IPs?
It works for either — the maths is the same, but private ranges (like 192.168.0.0/16) are reserved for internal networks.