How Many Hosts in a /26 Subnet? 62 Usable Addresses

A /26 subnet has 62 usable hosts. It contains 64 total addresses, and two of those are reserved: the network address and the broadcast address. That leaves 62 addresses you can actually assign to devices. If you want the answer confirmed against any prefix, run it through the IP Subnet Calculator.

What is the bit math behind 62?

An IPv4 address is 32 bits. The prefix tells you how many of those bits belong to the network. A /26 uses 26 bits for the network, so the remaining bits are host bits:

• 32 total bits, minus 26 network bits, equals 6 host bits.
• 6 host bits produce 2^6 = 64 total addresses.
• Subtract the network address and the broadcast address: 62 usable hosts.

Written as a formula, it is this:

usable = 2^(32 - prefix) - 2

Plug in 26: 2^(32 - 26) - 2 = 2^6 - 2 = 64 - 2 = 62. The same formula works for every prefix, which is why it is worth learning once instead of memorising a table. There is a fuller walkthrough of the formula in our guide on how to calculate usable hosts.

Why is it 62 and not 64?

Two addresses in every subnet are structurally spoken for. They are not assignable because they already mean something specific to the protocol. Both are defined by what the host bits look like:

• The network address is the one where all host bits are zero. It names the subnet itself. When you write 192.168.1.0/26, that .0 is the identifier for the block, not a device.
• The broadcast address is the one where all host bits are one. Traffic sent there is intended for every host in the subnet at once.

So the boundaries of the block are consumed by the block's own bookkeeping. With 6 host bits, the all-zeros pattern (000000) and the all-ones pattern (111111) are taken. The 62 patterns in between are yours.

This is also why the subtraction is always exactly 2, no matter the prefix. There is one all-zeros pattern and one all-ones pattern, never more. A /26 loses 2 out of 64. A /24 loses 2 out of 256. The cost is the same in absolute terms, which is why small subnets feel expensive: a /30 has 4 addresses and only 2 are usable.

What is the /26 subnet mask?

The /26 subnet mask is 255.255.255.192. The wildcard mask, which is the inverse and shows up in access control lists, is 0.0.0.63.

The last octet is where the interesting part happens. A mask of 192 in binary is 11000000. That is two network bits and six host bits in the final octet, matching the 24 bits already used by the first three octets. 24 + 2 = 26. The wildcard 63 is 00111111, the mirror image, and it maps directly onto the 64-address span.

That 192 in the mask also tells you the block size. 256 minus 192 equals 64, and 64 is exactly how far apart consecutive /26 networks sit. That shortcut is handy under exam pressure, and it is covered alongside every other prefix in the subnet mask cheat sheet.

How many /26 subnets fit in a /24?

Four. A /24 holds 256 addresses, and each /26 takes 64, so 256 divided by 64 is 4. Here are the four blocks laid out using 192.168.1.0/24 as the parent, with exact boundaries:

• 192.168.1.0/26, network .0, usable .1 to .62, broadcast .63
• 192.168.1.64/26, network .64, usable .65 to .126, broadcast .127
• 192.168.1.128/26, network .128, usable .129 to .190, broadcast .191
• 192.168.1.192/26, network .192, usable .193 to .254, broadcast .255

Read that list twice and the concept usually clicks. Notice the rhythm. Every network address is a multiple of 64: 0, 64, 128, 192. Every broadcast address is one less than the next network address. And every usable range is the 62 addresses squeezed between them.

Notice something else. The broadcast of the last block is .255, and the network of the first block is .0. Those are the same two addresses that a /24 would reserve. Subnetting a /24 into four /26 blocks does not just cost you those two, it costs you eight in total, two per block. That is the real price of splitting a network, and it is easy to forget when you are sizing address space. To sanity check any split, drop the parent network into the IP Subnet Calculator and compare the totals.

Is the answer 64 or 63?

Neither. Both are the classic wrong answers to this question, and each comes from a specific mistake worth naming.

64 is the total address count, not the usable count. It is the correct output of 2^6, so the arithmetic is right as far as it goes. The error is stopping one step early and forgetting the minus 2. If a question asks for hosts, addresses you can assign, or usable addresses, 64 is wrong. If it asks for the block size or total addresses, 64 is correct. Read the wording carefully.

63 comes from subtracting only one address. Usually the person remembered the broadcast address and forgot the network address, or the reverse. Two addresses are reserved, not one, so the subtraction is always minus 2. There is no prefix where you subtract just one.

A quick self check: your usable count for any standard subnet should be an even number, because the total is a power of two and you removed exactly two. 63 is odd, so it cannot be right. 62 is.

How does /26 compare to its neighbours?

Each step in the prefix halves or doubles the block. Moving from /26 to /27 cuts your usable hosts by more than half, because the fixed cost of two reserved addresses bites harder on smaller blocks.

• /24, mask 255.255.255.0, 256 total addresses, 254 usable
• /25, mask 255.255.255.128, 128 total addresses, 126 usable
• /26, mask 255.255.255.192, 64 total addresses, 62 usable
• /27, mask 255.255.255.224, 32 total addresses, 30 usable

This is the practical decision most people are really making. If you need to support 40 devices, a /26 fits with 22 addresses of headroom, while a /27 leaves you 10 short. If you need 100, a /26 will not do it and you want a /25. Size for growth, not for today's device count, because renumbering a live subnet later is far more painful than allocating a slightly larger block now.

Bottom line

A /26 subnet gives you 62 usable hosts: 64 total addresses, minus the network address and the broadcast address. The mask is 255.255.255.192, the block size is 64, and four /26 blocks fit neatly inside a /24. The formula behind it, 2^(32 - prefix) - 2, works for every prefix you will ever be asked about. When you need the ranges, masks and boundaries for a specific network without the mental arithmetic, use the IP Subnet Calculator.