Network Tools
Professional networking tools for subnetting, IP addressing, VLSM planning, and public IP lookups.
Network Calculators & IP Tools
IP & CIDR Calculator
- IPv4 subnet calculator
- CIDR conversion
- Broadcast address
- Wildcard mask
- Host range
IPv6 Calculator
- Expand / compress (RFC 5952)
- Nibble-boundary subnetting
- Hierarchical prefix splitting
- Address type detection
Why use these tools?
Network engineers plan and troubleshoot IPv4 addressing daily: sizing subnets for new sites, splitting a block into variable-length segments, or checking which country an unfamiliar IP belongs to. These calculators handle the arithmetic instantly and correctly, so you can focus on the design decisions rather than manual bit math.
Frequently asked questions
- Which tool should I use to plan subnets for a new site?
- Start with the VLSM Calculator if you need subnets sized to different host counts per segment. Use the IP & CIDR Calculator once you have a specific network and mask to break down or verify.
- Do these tools work for IPv6?
- The IP & CIDR Calculator and VLSM Calculator are IPv4-only. Use the dedicated IPv6 Calculator for IPv6 addressing. IP Country Lookup supports both IPv4 and IPv6 addresses.
- Is any of my data sent to a server?
- The IP & CIDR Calculator and VLSM Calculator run entirely in your browser; nothing is transmitted. IP Country Lookup sends the IP to our own server (never a third party) to resolve the country using a local database.