IP Address Range Calculator
Address counts across prefixes.
Enter your values
ⓘ Live results
Results
- Subnets available
- 256
- Addresses in parent
- 65,536
- Addresses per child
- 256
- Usable hosts per child
- 254
Quick answer
Each bit added to a prefix halves the number of addresses in the block.
Addresses = 2^(32 − prefix)
How to use the IP Address Range Calculator
- 1Enter the parent prefix you own.
- 2Enter the child prefix you want to carve out.
- 3Read how many subnets you get.
Worked example
Using the values the calculator loads with:
Inputs
- Parent prefix16
- Child prefix24
Results
- Subnets available256
- Addresses in parent65,536
- Addresses per child256
- Usable hosts per child254
Frequently asked questions
How many /24s in a /16?
256.
Does IPv6 work the same?
The maths is identical but with 128 bits instead of 32.
About this calculator
- Built and reviewed by James Whitfield · How we build and test calculators
- Report an error
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.