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Private IP address ranges at a glance
The first three rows are the private ranges. The other three are blocks that are not routed like public addresses.
| Block | Range | Addresses | Use |
|---|---|---|---|
| 10.0.0.0/8 | 10.0.0.0 to 10.255.255.255 | 16,777,216 | Private (RFC 1918) |
| 172.16.0.0/12 | 172.16.0.0 to 172.31.255.255 | 1,048,576 | Private (RFC 1918) |
| 192.168.0.0/16 | 192.168.0.0 to 192.168.255.255 | 65,536 | Private (RFC 1918) |
| 100.64.0.0/10 | 100.64.0.0 to 100.127.255.255 | 4,194,304 | Shared address space / carrier-grade NAT (RFC 6598) |
| 127.0.0.0/8 | 127.0.0.0 to 127.255.255.255 | 16,777,216 | Loopback |
| 169.254.0.0/16 | 169.254.0.0 to 169.254.255.255 | 65,536 | Link-local (APIPA) |
The three private ranges (RFC 1918)
- 10.0.0.0/8: 10.0.0.0 to 10.255.255.255, 16,777,216 addresses. The largest private block.
- 172.16.0.0/12: 172.16.0.0 to 172.31.255.255, 1,048,576 addresses. The 172 range ends at 172.31.255.255, so 172.32.0.1 is public.
- 192.168.0.0/16: 192.168.0.0 to 192.168.255.255, 65,536 addresses. The block most home and office routers use.
To see the size of any block, use the CIDR calculator. The subnet mask cheat sheet lists every prefix from /0 to /32.
Other special ranges
Shared address space (100.64.0.0/10) is used by carriers for carrier-grade NAT and is not an RFC 1918 private range. Loopback (127.0.0.0/8) stays on the device, and link-local addresses (169.254.0.0/16) are used on the local network when no address is assigned. The table adds the remaining special blocks.
| Block | Range | Addresses | Use |
|---|---|---|---|
| 0.0.0.0/8 | 0.0.0.0 to 0.255.255.255 | 16,777,216 | "This network" (source addresses only) |
| 192.0.2.0/24 | 192.0.2.0 to 192.0.2.255 | 256 | Documentation (RFC 5737) |
| 198.51.100.0/24 | 198.51.100.0 to 198.51.100.255 | 256 | Documentation (RFC 5737) |
| 203.0.113.0/24 | 203.0.113.0 to 203.0.113.255 | 256 | Documentation (RFC 5737) |
| 224.0.0.0/4 | 224.0.0.0 to 239.255.255.255 | 268,435,456 | Multicast |
| 240.0.0.0/4 | 240.0.0.0 to 255.255.255.255 | 268,435,456 | Reserved (future use) |
IPv6 has its own private range, unique local addresses (fc00::/7). To work with them, use the IPv6 subnet calculator.
How to check if an IP address is private
Compare the address with the three blocks: 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16. The page does this with a range test on the 32-bit value of the address. Examples:
- 10.20.30.40 is a private address (RFC 1918). It is inside 10.0.0.0/8.
- 172.31.255.255 is a private address (RFC 1918). It is inside 172.16.0.0/12.
- 172.32.0.1 is a public address. It is not inside any special-use range listed on this page.
- 192.168.0.1 is a private address (RFC 1918). It is inside 192.168.0.0/16.
Private addresses and NAT
Private addresses are not routed on the public internet. A router doing network address translation lets devices that use them reach the internet through one public address.
Frequently asked questions
What are the private IP address ranges?
The private IP address ranges are 10.0.0.0/8 (10.0.0.0 to 10.255.255.255), 172.16.0.0/12 (172.16.0.0 to 172.31.255.255) and 192.168.0.0/16 (192.168.0.0 to 192.168.255.255), defined in RFC 1918. They hold 16,777,216, 1,048,576 and 65,536 addresses. Any address outside them is not an RFC 1918 private address.
Is 172.32.0.1 a private IP address?
No. The private 172 range ends at 172.31.255.255, so 172.32.0.1 is public. The same is true just below the range: 172.15.0.1 is public, while 172.16.0.0 and 172.31.255.255 are private. Only second numbers 16 to 31 are private, which is why the block is written 172.16.0.0/12.
What is 100.64.0.0/10?
100.64.0.0/10 is shared address space for carrier-grade NAT (RFC 6598). It runs from 100.64.0.0 to 100.127.255.255 and holds 4,194,304 addresses. It is not an RFC 1918 private range, so this page labels 100.64.0.1 as Shared / CGNAT (RFC 6598) and does not call it Private.
Is 169.254.10.10 a private address?
No, it is a link-local address. The block is 169.254.0.0/16, and devices use it on their own when they cannot get an address from a server. The checker labels 169.254.10.10 as Link-local. It is not one of the three RFC 1918 private ranges and it stays on the local network.
Can a private IP address be reached from the internet?
Not directly. Private addresses are not routed on the public internet, so devices that use them reach the internet through a router doing network address translation. Two networks can both use 192.168.0.1 without clashing, but joining them later needs different ranges. Check an address in the checker before you plan.
How do I check whether an IP address is private?
Check whether it falls inside 10.0.0.0/8, 172.16.0.0/12 or 192.168.0.0/16. 10.20.30.40 and 192.168.0.1 are private, 8.8.8.8 is public, and 100.64.0.1 is shared CGNAT space. Type any single address in the checker above to see the verdict and the block it matched.