Calculate IP range

Calculate the inclusive size, endpoints, and CIDR blocks for an IPv4 range.

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ToolIP Range Calculator
Input
Output
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Preview

How it works

Start and end addresses become 32-bit integers; subtraction derives inclusive size and binary alignment produces optional CIDR blocks. The calculation is numeric and does not probe hosts.

  • Inclusive endpoints suit allocation lists.
  • CIDR decomposition is useful for routing and firewall rules.

Worked example

Calculate range for a /24 CIDR block
Get start IP, end IP, total addresses, and CIDR blocks for 10.0.0.0/24
Input
											10.0.0.0/24
Output
												Start IP: 10.0.0.0
End IP: 10.0.0.255
Total addresses: 256
Cidrs: 10.0.0.0/24
IP count: 256
Is subnet: yes
Start IP decimal: 167772160
End IP decimal: 167772415

When to use this

Firewalls, IPAM systems, and provider allocations calculate ranges.

Edge cases

  • A range past 255.255.255.255 is invalid rather than wrapping.
  • Inclusive count is end minus start plus one.
  • CIDR blocks can include non-assignable network or broadcast addresses.

References