IPv4 addresses form the foundation of modern networking, and understanding block sizes is essential for any business that buys, sells, or leases IP space. Whether you’re managing hosting infrastructure, running a VPN service, scaling a SaaS platform, or building new data-center capacity, knowing the right subnet to choose can help you optimize performance and control costs. This guide breaks down every common IPv4 block size from small allocations ideal for marketing campaigns to large subnets used by ISPs and enterprise networks.
Why IPv4 Block Sizes Matter for Today’s Networks
IPv4 addresses are arranged into subnets, each represented by CIDR notation (Classless Inter-Domain Routing). The smaller the subnet mask, the larger the block. Because IPv4 inventory is limited and costly, accurate planning prevents overspending and ensures long-term flexibility. Choosing the right block also improves routing efficiency, segmentation, allocation control, and abuse management.
Common IPv4 Block Sizes and What They’re Used For
/32 – Single IP Address
A single dedicated IPv4 address.
Use cases:
• Individual server assignment
• SSL-bound applications
• Targeted marketing or proxy rotation
• Static IP for remote systems
/31 – 2 IPs (1 usable)
Typically used for point-to-point connections.
Use cases:
• Router links
• Carrier-grade networks
/30 – 4 IPs (2 usable)
Ideal for network links requiring two usable addresses.
Use cases:
• Firewall-to-router links
• Small provider handoffs
/29 – 8 IPs (5 usable)
A minimal allocation for hosting or small deployments.
Use cases:
• Small VPN clusters
• Lightweight hosting instances
• Network testing
/28 – 16 IPs (13 usable)
Good for small businesses needing a controlled range.
Use cases:
• Multi-server environments
• Email marketing operations
• Lightweight ISP or VoIP usage
/27 – 32 IPs (29 usable)
A popular choice for small to medium deployments.
Use cases:
• VPN companies
• Marketing operations
• Managed hosting providers
/26 – 64 IPs (61 usable)
Useful when you require more routing flexibility and separation.
Use cases:
• SaaS workloads
• Cloud services
• Larger VPN clusters
/25 – 128 IPs (125 usable)
Often selected by hosting and telecom companies.
Use cases:
• CDN nodes
• Proxy networks
• Shared hosting clusters
/24 – 256 IPs (251 usable)
The most requested block worldwide.
Use cases:
• ISPs and MSPs
• VPN/Proxy businesses
• Email service providers
• Large customer segmentation
/23 – 512 IPs (507 usable)
A step up for enterprises needing significant allocation.
Use cases:
• Scalable cloud hosting
• Regional ISP expansion
• Corporate multi-zone networks
/22 – 1,024 IPs (1,019 usable)
Ideal for ISPs, data centers, and global platforms.
Use cases:
• Carrier operations
• Multi-tenant environments
• Large-scale SaaS and hosting
/21 – 2,048 IPs (2,043 usable)
A heavy-capacity block for advanced infrastructure.
Use cases:
• Telecom carriers
• Large hosting platforms
• Distributed cloud environments
/20 – 4,096 IPs (4,091 usable)
Often used by high-traffic providers.
Use cases:
• Regional ISP network
• Enterprise-scale operations
• International service expansion
Blocks larger than/20 (such as /19, /18, /16, etc.) are still used but are rarely available for purchase due to global scarcity. These are typically held by legacy holders, telecom giants, and governments.
Choosing the Right IPv4 Block for Your Needs
Selecting the correct block size depends on:
• Your current network size
• Anticipated scaling requirements
• RIR policy constraints (ARIN, RIPE, APNIC, LACNIC)
• Budget and IPv4 market pricing
• Minimum allocations allowed by your region
Many companies start with a /24 block because it provides full control, reverse DNS flexibility, and enough space for growth. However, leasing is often preferred when scaling fast without a large upfront investment.
How IPv4Hub.net Supports Your IPv4 Block Needs
IPv4Hub.net helps businesses acquire IPv4 blocks safely, quickly, and with full compliance across ARIN, RIPE, APNIC, and LACNIC regions. The platform verifies IP ownership, checks for blacklist status, and ensures clean, legitimate inventory before delivering it to clients. Whether you need a single /24 or a multi-block request for expansion, IPv4Hub.net handles sourcing, escrow, documentation, and transfer assistance to make the process smooth and reliable.
Optimizing Your Network with the Right IPv4 Block
Understanding IPv4 block sizes enables you to plan infrastructure efficiently, avoid overpaying, and maintain long-term network stability. With expert brokers like IPv4Hub.net, businesses can acquire clean, verified IPv4 space that matches their technical requirements and future goals. Whether you are expanding hosting capacity, launching a VPN network, or scaling global infrastructure, choosing the right block is the first step toward reliable digital growth. Find IPv4 market updates on IPv4Hub