Public IP Planner
Plan and allocate public IP address requirements across cloud resources.
About Public IP Planner
Public IP planning sums every service that requires direct internet-routable addressing — load balancers, bastion hosts, VPN endpoints — plus the IPs consumed by NAT gateways (which need at least one public IP each, more if scaling for port capacity), then applies a redundancy multiplier to account for standby capacity, multi-AZ duplication, or failover requirements. Cloud providers often charge per allocated public IP and increasingly charge for idle ones too, so right-sizing this number avoids both under-provisioning (risking port exhaustion or availability gaps) and unnecessary ongoing cost.
Formula
Total public IPs needed
total_ips = (direct_services + nat_gateways × ips_per_gateway) × redundancy_factor
- s
- Services needing a direct public IP
- g
- Number of NAT gateways
- p
- IPs per NAT gateway
- r
- Redundancy multiplier
Worked example
With the default values below, Public IP Planner returns Total Public IPs Needed of 12. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Services Requiring a Direct Public IPminimum 0
- 3
- NAT Gatewaysminimum 0
- 3
- IPs per NAT Gatewayaccepts 1–8
- 1
- Redundancy Multiplierminimum 1
- 2
Results
- Total Public IPs Needed
- 12
- Base IPs (no redundancy)
- 6
- IPs for NAT Gateways
- 3
- Additional IPs for Redundancy
- 6
Step by step
- 1Values used
- 2Total public IPs needed
- 3Total Public IPs Needed= 12
- 4Base IPs (no redundancy)= 6
- 5IPs for NAT Gateways= 3
- 6Additional IPs for Redundancy= 6
Assumptions and limits
- The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax or compounding frequency into account.
- Figures are rounded for display to whole numbers, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
Why does redundancy multiply IP count instead of just adding a fixed number?
Redundancy needs typically scale with the size of the base deployment — doubling capacity for active/standby or multi-AZ resilience means doubling every category of public-facing resource, not just adding a flat buffer, which is why a multiplier models it more accurately than a fixed addend.
Why might a NAT gateway need more than one public IP?
Additional IPs on a NAT gateway multiply its available port pool for connections to any single destination (see the NAT Gateway Capacity calculator) — high-connection-volume workloads to a small number of destinations sometimes need multiple IPs per gateway to avoid port exhaustion.
Do all cloud providers charge for public IPs the same way?
No — pricing models vary and change over time; some providers now charge hourly for any allocated public IPv4 address regardless of use, including idle ones. Check your specific provider's current pricing tools for exact costs rather than assuming a flat rate.
Should private services be included in this count?
No — this planner is specifically for internet-routable public IPs. Services accessible only within your VPC/VNet or over private connectivity (VPN, Direct Connect, ExpressRoute) don't need public IPs and should be planned using the Private IP Planner calculator instead.