Everyday Converters
IP Subnet Calculator
Calculate IPv4 subnet address counts and usable hosts from CIDR prefix.
Result
--What does this calculator do?
Calculate IPv4 subnet address counts and usable hosts from CIDR prefix.
Formula
IPv4 subnet size = 2^(32 − CIDR prefix).
Example calculation
/24 has 256 addresses and usually 254 usable hosts.
Common use cases
- Network planning
- CIDR checks
- Subnet sizing
Limitations and accuracy notes
This calculator is for quick planning and education. Results depend on your inputs and may not include every real-world rule, fee, tax, health factor, local requirement, or professional standard.
IP Subnet Calculator FAQ
Is this calculator free?
Yes. It gives quick estimates directly in your browser.
Should I use this as professional advice?
No. Use it as a planning aid and confirm important decisions with a qualified professional.