Heapcider Tools

IPv4 CIDR

CIDR Calculator

A fast IPv4 CIDR calculator for network, cloud, and security workflows.

IPv4 only

Convert IP range to CIDR

Enter the first and last IPv4 address. Pasted ranges work too.

CIDR Calculator

Convert IP ranges, inspect CIDR blocks, and check IPv4 membership quickly.

Examples

  • 192.168.0.0 - 192.168.0.255
  • 10.0.0.0/24
  • 10.0.0.42 in 10.0.0.0/24

Common mistakes

  • Mixing IPv4 and IPv6 formats in the same calculation.
  • Reversing the start and end IP when converting a range.
  • Trying to export very large blocks instead of using the preview.

FAQ

Does this tool support IPv6?

This MVP is IPv4-only so the interface stays fast and predictable.

Are calculations sent to a server?

No. The calculator runs in the browser and does not need an API backend.

Why is the IP list preview capped?

Large CIDR blocks can contain millions of addresses, so the page shows a short preview and protects full exports with a separate limit.