# /13 Subnet Mask (255.248.0.0) – Hosts, Range & FAQ

> The /13 subnet mask is 255.248.0.0. A /13 block holds 524,288 addresses with 524,286 usable hosts — ranges, wildcard, binary math and FAQs.

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# /13 Subnet Mask ReferenceIPv4

Eight consecutive /16s summarized in one line: mask 255.248.0.0, 524,288 addresses. A /13 is sized for a national ISP region and rare enough that spotting one in a design review starts a conversation.

The /13 subnet mask is 255.248.0.0, equivalent to 0.7.255.255 as a wildcard. A /13 block contains 524,288 IP addresses (524,286 usable hosts).

## /13 facts at a glance

- **Subnet mask:** 255.248.0.0
- **Wildcard mask:** 0.7.255.255
- **Binary mask:** 11111111.11111000.00000000.00000000
- **Total addresses:** 524,288
- **Usable hosts:** 524,286 (excludes network & broadcast)
- **Block size:** 524,288 addresses (219)
- **Typical role:** Large enterprise and carrier aggregation

## Example /13 networks

Three consecutive /13 blocks, starting at the /13 boundary that contains 198.51.100.0:

| Network | Usable range | Usable hosts |
| --- | --- | --- |
| 198.48.0.0/13 | 198.48.0.1 – 198.55.255.254 | 524,286 |
| 198.56.0.0/13 | 198.56.0.1 – 198.63.255.254 | 524,286 |
| 198.64.0.0/13 | 198.64.0.1 – 198.71.255.254 | 524,286 |

## How to calculate a /13 mask

A /13 mask sets the first 13 bits of a 32-bit number to 1 and leaves the remaining 19 bits as 0. In binary that reads `11111111.11111000.00000000.00000000`, which converts to dotted decimal `255.248.0.0`. Each block covers a contiguous run of 219 = 524,288 addresses, and every block starts at a multiple of that size. The wildcard simply flips every bit, giving `0.7.255.255`.

## Where /13 is used

- Regional aggregation planning for large network operators.
- Structured multi-campus addressing where each child site takes a /16 or smaller.
- Advanced coursework on masks that stop five bits into the second octet.

Worked example: 88.0.0.0/13 spans 88.0.0.0 through 95.255.255.255, eight complete /8s swallowed by a single summary.

## Frequently asked questions

**What is the mask for a /13?**

255.248.0.0, wildcard 0.7.255.255.

**How many addresses are in a /13?**

524,288 total and 524,286 usable by convention.

**How many /16s are in a /13?**

Eight. Equivalently, a /13 contains 2,048 /24-sized networks.

## Open this block in a calculator

[Open the /13 block in the subnet calculator](https://itinsighthub.com/subnet-calculator/?q=198.48.0.0%2F13)

[Get the /13 wildcard mask →](https://itinsighthub.com/wildcard-mask-calculator/?q=%2F13)

### Related prefixes

[/12](https://itinsighthub.com/subnet/12/)[/14](https://itinsighthub.com/subnet/14/)[/24](https://itinsighthub.com/subnet/24/)[/26](https://itinsighthub.com/subnet/26/)[/28](https://itinsighthub.com/subnet/28/)[/30](https://itinsighthub.com/subnet/30/)

← /12 subnet mask
/14 subnet mask →

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