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52 calculators

Computing & networking calculators

Subnets, transfer times, storage, encoding bitrates and display geometry, keeping decimal and binary prefixes apart.

A–Z index of all calculators

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A
B
C
D
H
I
L
M
P
R
S
U
V

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/1 subnet A /1 IPv4 subnet has a mask of 128.0.0.0, 2,147,483,648 addresses and 2,147,483,646 usable hosts. Work out blocks, splits and address budgets.
/10 subnet A /10 IPv4 subnet has a mask of 255.192.0.0, 4,194,304 addresses and 4,194,302 usable hosts. Work out blocks, splits and address budgets.
/11 subnet A /11 IPv4 subnet has a mask of 255.224.0.0, 2,097,152 addresses and 2,097,150 usable hosts. Work out blocks, splits and address budgets.
/12 subnet A /12 IPv4 subnet has a mask of 255.240.0.0, 1,048,576 addresses and 1,048,574 usable hosts. Work out blocks, splits and address budgets.
/13 subnet A /13 IPv4 subnet has a mask of 255.248.0.0, 524,288 addresses and 524,286 usable hosts. Work out blocks, splits and address budgets.
/14 subnet A /14 IPv4 subnet has a mask of 255.252.0.0, 262,144 addresses and 262,142 usable hosts. Work out blocks, splits and address budgets.
/15 subnet A /15 IPv4 subnet has a mask of 255.254.0.0, 131,072 addresses and 131,070 usable hosts. Work out blocks, splits and address budgets.
/16 subnet A /16 IPv4 subnet has a mask of 255.255.0.0, 65,536 addresses and 65,534 usable hosts. Work out blocks, splits and address budgets.
/17 subnet A /17 IPv4 subnet has a mask of 255.255.128.0, 32,768 addresses and 32,766 usable hosts. Work out blocks, splits and address budgets.
/18 subnet A /18 IPv4 subnet has a mask of 255.255.192.0, 16,384 addresses and 16,382 usable hosts. Work out blocks, splits and address budgets.
/19 subnet A /19 IPv4 subnet has a mask of 255.255.224.0, 8,192 addresses and 8,190 usable hosts. Work out blocks, splits and address budgets.
/2 subnet A /2 IPv4 subnet has a mask of 192.0.0.0, 1,073,741,824 addresses and 1,073,741,822 usable hosts. Work out blocks, splits and address budgets.
/20 subnet A /20 IPv4 subnet has a mask of 255.255.240.0, 4,096 addresses and 4,094 usable hosts. Work out blocks, splits and address budgets.
/21 subnet A /21 IPv4 subnet has a mask of 255.255.248.0, 2,048 addresses and 2,046 usable hosts. Work out blocks, splits and address budgets.
/22 subnet A /22 IPv4 subnet has a mask of 255.255.252.0, 1,024 addresses and 1,022 usable hosts. Work out blocks, splits and address budgets.
/23 subnet A /23 IPv4 subnet has a mask of 255.255.254.0, 512 addresses and 510 usable hosts. Work out blocks, splits and address budgets.
/24 subnet A /24 IPv4 subnet has a mask of 255.255.255.0, 256 addresses and 254 usable hosts. Work out blocks, splits and address budgets.
/25 subnet A /25 IPv4 subnet has a mask of 255.255.255.128, 128 addresses and 126 usable hosts. Work out blocks, splits and address budgets.
/26 subnet A /26 IPv4 subnet has a mask of 255.255.255.192, 64 addresses and 62 usable hosts. Work out blocks, splits and address budgets.
/27 subnet A /27 IPv4 subnet has a mask of 255.255.255.224, 32 addresses and 30 usable hosts. Work out blocks, splits and address budgets.
/28 subnet A /28 IPv4 subnet has a mask of 255.255.255.240, 16 addresses and 14 usable hosts. Work out blocks, splits and address budgets.
/29 subnet A /29 IPv4 subnet has a mask of 255.255.255.248, 8 addresses and 6 usable hosts. Work out blocks, splits and address budgets.
/3 subnet A /3 IPv4 subnet has a mask of 224.0.0.0, 536,870,912 addresses and 536,870,910 usable hosts. Work out blocks, splits and address budgets.
/30 subnet A /30 IPv4 subnet has a mask of 255.255.255.252, 4 addresses and 2 usable hosts. Work out blocks, splits and address budgets.
/31 subnet A /31 IPv4 subnet has a mask of 255.255.255.254, 2 addresses and 2 usable hosts. Work out blocks, splits and address budgets.
/32 subnet A /32 IPv4 subnet has a mask of 255.255.255.255, 1 addresses and 1 usable hosts. Work out blocks, splits and address budgets.
/4 subnet A /4 IPv4 subnet has a mask of 240.0.0.0, 268,435,456 addresses and 268,435,454 usable hosts. Work out blocks, splits and address budgets.
/5 subnet A /5 IPv4 subnet has a mask of 248.0.0.0, 134,217,728 addresses and 134,217,726 usable hosts. Work out blocks, splits and address budgets.
/6 subnet A /6 IPv4 subnet has a mask of 252.0.0.0, 67,108,864 addresses and 67,108,862 usable hosts. Work out blocks, splits and address budgets.
/7 subnet A /7 IPv4 subnet has a mask of 254.0.0.0, 33,554,432 addresses and 33,554,430 usable hosts. Work out blocks, splits and address budgets.
/8 subnet A /8 IPv4 subnet has a mask of 255.0.0.0, 16,777,216 addresses and 16,777,214 usable hosts. Work out blocks, splits and address budgets.
/9 subnet A /9 IPv4 subnet has a mask of 255.128.0.0, 8,388,608 addresses and 8,388,606 usable hosts. Work out blocks, splits and address budgets.

A

B

C

D

H

Hash collision probability Birthday-problem collision odds for a hash of a given size over a number of items.

I

IP address planning Address budget for a network with growth headroom, and the prefix that covers it.

L

Little's law Little's law plus the M/M/1 waiting time, for capacity planning under load.

M

mAh to watt-hours Convert battery capacity between milliamp-hours and watt-hours, with airline limits.

P

Password entropy Entropy in bits from length and alphabet, with the time to exhaust it at a given guess rate.

R

RAID capacity Usable capacity, fault tolerance and read speed for common RAID levels.

S

U

Uptime and SLA Allowed downtime for an availability target, per day, month and year.

V

Video file size File size from bitrate and duration, and the bitrate that fits a target size.

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