~ / subnet

$ ipcalc 10.0.0.0/22

Subnet Calculator

Network and broadcast addresses, usable host ranges and mask conversions for IPv4 and IPv6 — plus splitting a block into smaller ones. Everything is worked out from the address you enter; nothing is looked up anywhere.

$

CIDR, dotted mask or a bare address.

 
ipcalc 10.0.0.0/22
Address: 10.0.0.0 00001010.00000000.00000000.00000000
Netmask: 255.255.252.0 = 22 11111111.11111111.11111100.00000000
Wildcard: 0.0.3.255 00000000.00000000.00000011.11111111
=>
Network: 10.0.0.0/22 00001010.00000000.00000000.00000000
HostMin: 10.0.0.1
HostMax: 10.0.3.254
Broadcast: 10.0.3.255
Hosts/Net: 1,022 Class A, private
#

details

Details for 10.0.0.0/22
network 10.0.0.0/22
netmask255.255.252.0 = /22
wildcard0.0.3.255
first host10.0.0.1
last host10.0.3.254
broadcast 10.0.3.255
total addresses1,024
usable hosts1,022
scopeprivate
classA — classful, informational only
reverse zone0.0.0.10.in-addr.arpa
#

prefix reference

prefixnetmaskaddressesusable hosts
/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

A /31 has no network or broadcast address to reserve, so both addresses are usable on a point-to-point link (RFC 3021). A /32 is a single host.