Netcalc
Small calculators for the sums that come up on every shift. They run entirely in your browser: nothing you type is sent anywhere. Each one shows its formula and a worked example on its page, so you can check the numbers by hand.
- IPv4 subnet calculator
network, broadcast, usable range, mask and wildcard for any CIDR block, plus a split into smaller subnets.
- SNMP counter to bit rate
two octet-counter readings to bits per second and utilization, with 32-bit wrap handling.
- Uptime and SLA calculator
allowed downtime for any availability target, achieved uptime from an outage log, and serial or parallel paths.
- Transfer time and bandwidth
how long a file or backup takes over a given link, and the link a deadline needs.
- PoE budget calculator
power for access points, cameras and phones against a switch PoE budget, with headroom.