IPv6 Subnet Calculator
Calculate IPv6 network addresses, prefix boundaries, and address ranges. The essential companion to our IPv4 subnet calculator for dual-stack network planning.
IPv6 Subnet Calculator
Calculate IPv6 network addresses, ranges, and prefix details
Quick examples:
Common IPv6 Prefix Lengths
| Prefix | Common Use | Addresses |
|---|---|---|
| /128 | Loopback / single host | 1 |
| /127 | Point-to-point link | 2 |
| /64 | Standard LAN subnet | ~1.8×10¹⁹ |
| /56 | Residential allocation | ~4.7×10²¹ |
| /48 | Standard site allocation | ~1.2×10²⁴ |
| /32 | ISP allocation from RIR | ~7.9×10²⁸ |
| /16 | Large ISP block | ~5.2×10³³ |
IPv6 Subnetting Fundamentals
IPv6 uses 128-bit addresses (vs 32-bit in IPv4), providing a vastly larger address space. The standard subnet for a LAN is /64, which gives each network 2⁶⁴ addresses — more than enough for any local network.
IPv6 vs IPv4 Subnetting
- 128-bit addresses vs 32-bit
- Standard LAN prefix: /64 (vs variable in IPv4)
- No broadcast addresses in IPv6
- Hex notation with colons instead of decimal with dots
- :: shorthand for consecutive zero groups
Common Allocations
- /32 — ISP allocation from Regional Internet Registry
- /48 — Standard site allocation (most common)
- /56 — Residential / small site allocation
- /64 — Single LAN subnet
- /128 — Single host (loopback)