CIDRworkbench
IPv4 + IPv6

NETWORK TOOLKIT / 01

Cloud Subnet Calculator.

Subnet capacity and reservations for AWS, Azure, and Google Cloud.

01

Define your network

Or use an IPv4 address and mask: 192.168.10.1 255.255.255.0

TRY
NETWORK OVERVIEWPrivate Network

10.0.0.0/24

Total Addresses256
Usable Addresses251
Prefix Length/24

Usable addresses exclude the selected provider’s reservations. See the profile rules below.

FIRST USABLE10.0.0.4
LAST USABLE10.0.0.254
Network Address10.0.0.0
Last Address10.0.0.255
Subnet Mask255.255.255.0
Wildcard Mask0.0.0.255
Broadcast Address10.0.0.255
Address TypePrivate Network
02

Inside the address

32 bits · 4 octets
00001010
10
00000000
0
00000000
0
00000000
0
Network · 24 bitsHost · 8 bits
Reverse DNS & Delegation

PTR name for the input address

0.0.0.10.in-addr.arpa.

Network delegation

0.0.10.in-addr.arpa.
AWS VPC Rules

IPv4 /16–/28: first 4 and last address reserved. IPv6 /44–/64 in steps of 4: first 4 and last address reserved. BYOIP exceptions and service quotas are outside this profile.

Provider / Standard Reference ↗

Cloud profiles model subnet size and reservations, not full deployment eligibility. IPv6 total address space is not an assignable-host count.

A /24 Has 256 Addresses. Usable Capacity Depends on the Profile.

Choose AWS VPC, Azure VNet or the appropriate Google Cloud range type in the calculator. The profile adjusts IPv4 usable capacity and warns when a prefix is outside the modeled subnet limits.

Capacity of 10.0.0.0/24 before service-specific consumption
ProfileReservedUsableAssignable Range
Standard LAN225410.0.0.1–10.0.0.254
AWS VPC525110.0.0.4–10.0.0.254
Azure VNet525110.0.0.4–10.0.0.254
Google Cloud Primary425210.0.0.2–10.0.0.253
Google Cloud Secondary025610.0.0.0–10.0.0.255

Size the Subnet, Then Check the Deployment

For 250 IPv4 hosts and 10% growth, the planner rounds the requirement to 275. An AWS /24 has only 251 usable addresses; a /23 has 507 and meets that capacity requirement. Service-specific address consumption can require additional space.

These profiles model subnet prefix limits and reservations. They do not validate all address-range eligibility, BYOIP exceptions, regional availability or service-specific deployment quotas. IPv6 totals describe address space; provider IPv6 allocation notes are shown separately. Consult the provider documentation for the intended deployment.

Select Plan Within This Network to carry the current CIDR and profile into the Subnet Planner, then review its allocation preview before applying.

Provider References