/15 subnet: mask 255.254.0.0, 131,072 addresses

Everything about a /15 network, with the CIDR calculator pre-filled — change the IP to calculate your own block.

Enter a CIDR range above to calculate

Is an IP inside a CIDR block?

Yes — 10.0.42.7 is inside 10.0.0.0/16.

Do two CIDR blocks overlap?

Overlap — 10.0.128.0/20 sits inside 10.0.0.0/16 (10.0.128.0 – 10.0.143.255).

CIDR blocks never partly overlap: one is inside the other, or they don't touch at all. Overlapping VPCs can't be peered.

/15 at a glance

Subnet mask
255.254.0.0
Wildcard mask
0.1.255.255
Mask in binary
11111111.11111110.00000000.00000000
Host bits
17
Total addresses
131,072
Usable hosts
131,070 (network and broadcast address excluded)
Equivalent /24 networks
512

Splitting a /15 into smaller subnets

  • 2 × /16 — 65,536 addresses each (65,534 usable)
  • 4 × /17 — 32,768 addresses each (32,766 usable)
  • 8 × /18 — 16,384 addresses each (16,382 usable)
  • 16 × /19 — 8,192 addresses each (8,190 usable)

Frequently asked

What is the subnet mask for /15?

255.254.0.0. The first 15 bits are network bits and the remaining 17 are host bits; the wildcard (inverse) mask is 0.1.255.255.

How many IP addresses are in a /15?

131,072 in total. 131,070 of them can be assigned to hosts, because the first is the network address and the last is the broadcast address.

CIDR to subnet mask cheat sheet

CIDRSubnet maskAddressesUsable hosts
/8255.0.0.016,777,21616,777,214
/12255.240.0.01,048,5761,048,574
/16255.255.0.065,53665,534
/17255.255.128.032,76832,766
/18255.255.192.016,38416,382
/19255.255.224.08,1928,190
/20255.255.240.04,0964,094
/21255.255.248.02,0482,046
/22255.255.252.01,0241,022
/23255.255.254.0512510
/24255.255.255.0256254
/25255.255.255.128128126
/26255.255.255.1926462
/27255.255.255.2243230
/28255.255.255.2401614
/29255.255.255.24886
/30255.255.255.25242
/31255.255.255.25422
/32255.255.255.25511
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