Linux & Unix Calculators
File systems, storage, memory, CPU, processes, permissions, security and system administration.
233 of 233 available now
- CPU Utilization CalculatorCalculate CPU utilization percentage from user, system and idle time measurements.
- Load Average CalculatorInterpret 1, 5 and 15-minute load averages relative to available CPU cores.
- CPU Core Requirement CalculatorCalculate the number of CPU cores needed to handle a target workload and concurrency.
- CPU Frequency CalculatorCalculate effective CPU clock frequency accounting for turbo boost and throttling.
- CPU Bottleneck CalculatorIdentify whether CPU is the limiting resource by comparing load, wait and I/O metrics.
- CPU Scheduling CalculatorCalculate process scheduling time slices under the Linux CFS scheduler.
- Context Switch CalculatorEstimate context switch overhead and its impact on effective CPU throughput.
- Interrupt Rate CalculatorCalculate hardware interrupt rate per second and its CPU overhead impact.
- System Load CalculatorCalculate overall system load combining CPU, I/O wait and runnable process counts.
- Thread Count CalculatorCalculate optimal thread count for a workload based on core count and I/O wait ratio.
- Process Count CalculatorCalculate maximum concurrent processes supportable given CPU and memory constraints.
- CPU Affinity CalculatorCalculate CPU affinity masks for pinning processes to specific cores with taskset.
File System
All 20 File System calculators →- File Size CalculatorConvert file sizes between bytes, KB, MB, GB and TB with binary or decimal units.
- Directory Size CalculatorEstimate total directory size from file counts and average file sizes.
- Disk Usage CalculatorCalculate used, free and total disk space percentages for a Linux filesystem.
- Filesystem Utilization CalculatorDetermine filesystem capacity utilization and headroom before hitting full disk alerts.
- Inode Usage CalculatorCalculate inode consumption and remaining inode capacity on an ext4 or xfs filesystem.
- Block Size CalculatorCalculate the number of disk blocks required to store a file given the filesystem block size.
- Filesystem Overhead CalculatorEstimate metadata and journaling overhead a filesystem subtracts from raw partition capacity.
- Mount Point Capacity CalculatorCalculate available capacity across multiple mount points sharing an underlying volume.
- Disk Growth EstimatorProject when a disk volume will run out of space based on its current growth rate.
- Partition Size PlannerPlan partition sizes for root, home, var and swap based on total disk capacity.
- Swap Size CalculatorRecommend swap partition or swap file size based on installed RAM and workload type.
- Filesystem Resize CalculatorCalculate new usable capacity after growing or shrinking a filesystem or partition.
Linux & System Administration
All 73 Linux & System Administration calculators →- File Permission (chmod) CalculatorWork out file permission (chmod) instantly with clear inputs, formula shown and shareable results.
- Octal Permission Converter CalculatorWork out octal permission converter instantly with clear inputs, formula shown and shareable results.
- umask Value CalculatorWork out umask value instantly with clear inputs, formula shown and shareable results.
- SUID SGID Sticky Bit CalculatorWork out suid sgid sticky bit instantly with clear inputs, formula shown and shareable results.
- Filesystem Inode Requirement CalculatorWork out filesystem inode requirement instantly with clear inputs, formula shown and shareable results.
- Block Size Overhead CalculatorWork out block size overhead instantly with clear inputs, formula shown and shareable results.
- Partition Size Plan CalculatorWork out partition size plan instantly with clear inputs, formula shown and shareable results.
- LVM Sizing CalculatorWork out lvm sizing instantly with clear inputs, formula shown and shareable results.
- Tmpfs Sizing CalculatorWork out tmpfs sizing instantly with clear inputs, formula shown and shareable results.
- RAID Rebuild Time CalculatorWork out raid rebuild time instantly with clear inputs, formula shown and shareable results.
- RAID Failure Probability CalculatorWork out raid failure probability instantly with clear inputs, formula shown and shareable results.
- Disk IOPS From Spindles CalculatorWork out disk iops from spindles instantly with clear inputs, formula shown and shareable results.
- RAM Usage CalculatorCalculate used, free and cached RAM percentages from free command output values.
- Memory Utilization CalculatorCalculate overall memory utilization percentage across physical RAM and swap.
- Swap Utilization CalculatorCalculate swap space usage percentage and estimate performance impact of swapping.
- Page Cache CalculatorCalculate the portion of RAM used as page cache and its effect on available memory.
- Buffer Cache CalculatorEstimate buffer cache size used for block device I/O buffering on Linux systems.
- Shared Memory CalculatorCalculate System V or POSIX shared memory segment size requirements for applications.
- HugePages CalculatorCalculate the number of HugePages needed to back a given amount of application memory.
- Kernel Memory CalculatorEstimate kernel memory footprint including slab allocations and kernel structures.
- Memory Leak EstimatorEstimate time until out-of-memory based on observed process memory leak rate.
- OOM Killer Threshold CalculatorCalculate the memory threshold at which the Linux OOM killer is likely to trigger.
- NUMA Memory PlannerPlan memory allocation across NUMA nodes to minimize remote memory access latency.
- Virtual Memory CalculatorCalculate virtual address space size and mapping requirements for a process.
Networking
All 20 Networking calculators →- Socket Count CalculatorCalculate maximum concurrent socket connections supportable by system file descriptor limits.
- TCP Connection CalculatorCalculate maximum concurrent TCP connections a server can handle given port and memory limits.
- UDP Port CalculatorCalculate available UDP port range and usable ports after reserved and ephemeral ranges.
- Network Buffer Size CalculatorCalculate optimal socket send/receive buffer sizes based on bandwidth and latency.
- MTU CalculatorCalculate maximum transmission unit and payload size after protocol header overhead.
- MSS CalculatorCalculate maximum segment size from MTU by subtracting TCP/IP header overhead.
- TCP Window Size CalculatorCalculate optimal TCP window size from bandwidth-delay product for maximum throughput.
- Bandwidth Utilization CalculatorCalculate network bandwidth utilization percentage against interface link capacity.
- Packet Rate CalculatorCalculate packets-per-second rate and its CPU load impact on network interrupt handling.
- NIC Throughput CalculatorCalculate achievable throughput of a network interface card given link speed and overhead.
- Interface Queue CalculatorCalculate network interface queue length needed to avoid packet drops under burst load.
- Bonding Capacity CalculatorCalculate aggregate bandwidth capacity of a bonded network interface across multiple NICs.
Processes
All 20 Processes calculators →- PID Range CalculatorCalculate PID exhaustion risk from pid_max and current process creation rate.
- Zombie Process RatioCalculate the ratio of zombie processes to total processes on a running system.
- Fork Rate CalculatorCalculate process fork rate per second and its impact on system overhead.
- Process Lifetime CalculatorCalculate average process lifetime and turnover rate from start and end timestamps.
- Cron Schedule CalculatorParse and explain a cron expression, showing the resulting execution schedule.
- Cron Next Run CalculatorCalculate the next several run times for a given cron expression and timezone.
- at Job Scheduler CalculatorCalculate the exact execution time for a one-off job scheduled with the at command.
- systemd Service Dependency CalculatorCalculate systemd unit startup order and dependency chain resolution time.
- Service Restart Delay CalculatorCalculate cumulative restart delay for a systemd service using exponential backoff.
- Daemon Count CalculatorCalculate the number of background daemons running and their aggregate resource usage.
- Open File Descriptor CalculatorCalculate open file descriptor usage against system and per-process ulimit thresholds.
- ulimit CalculatorCalculate recommended ulimit values for file descriptors, processes and memory.
Security
All 20 Security calculators →- File Permission CalculatorConvert Linux file permissions between octal, symbolic and chmod notation instantly.
- Octal Permission CalculatorConvert numeric octal permission codes like 755 or 644 into readable rwx notation.
- Symbolic Permission CalculatorConvert symbolic permission strings like rwxr-xr-- into octal chmod values.
- SUID CalculatorCalculate the resulting permission bits and security implications of setting the SUID bit.
- SGID CalculatorCalculate the resulting permission bits and behavior of setting the SGID bit on files or directories.
- Sticky Bit CalculatorCalculate the resulting permission bits of setting the sticky bit on shared directories.
- ACL Permission CalculatorCalculate effective access permissions when POSIX ACLs override standard file mode bits.
- SELinux Context CalculatorDecode SELinux security context labels into user, role, type and sensitivity components.
- AppArmor Profile CalculatorEstimate AppArmor profile rule coverage and enforcement mode impact on an application.
- SSH Key Length CalculatorCompare SSH key algorithm and bit-length strength across RSA, ECDSA and Ed25519.
- SSH Connection Capacity CalculatorCalculate maximum concurrent SSH sessions supportable under sshd MaxSessions and MaxStartups.
- SSH Session Timeout CalculatorCalculate SSH idle session timeout from ClientAliveInterval and ClientAliveCountMax settings.
Storage
All 20 Storage calculators →- LVM PV Size CalculatorCalculate LVM physical volume size and metadata overhead for a given block device.
- LVM VG Capacity CalculatorCalculate total volume group capacity from combined physical volume extents.
- LVM LV Size CalculatorCalculate logical volume size allocation from available volume group extents.
- LVM Snapshot Size CalculatorSize an LVM snapshot volume based on expected change rate and snapshot lifetime.
- RAID 0 Capacity CalculatorCalculate total usable capacity and performance of a RAID 0 striped array.
- RAID 1 Capacity CalculatorCalculate usable capacity of a RAID 1 mirrored array from disk count and size.
- RAID 5 Capacity CalculatorCalculate usable capacity of a RAID 5 array accounting for single-disk parity.
- RAID 6 Capacity CalculatorCalculate usable capacity of a RAID 6 array accounting for dual-disk parity.
- RAID 10 Capacity CalculatorCalculate usable capacity of a RAID 10 striped-mirror array from disk count and size.
- RAID Performance CalculatorEstimate combined read and write IOPS across a RAID array based on level and disk count.
- Disk IOPS CalculatorCalculate achievable disk IOPS from rotational speed, seek time and queue depth.
- Disk Throughput CalculatorCalculate sequential read/write throughput in MB/s from block size and IOPS.
System Administration
All 20 System Administration calculators →- Boot Time CalculatorBreak down system boot time across firmware, kernel and systemd unit startup phases.
- Kernel Parameter CalculatorCalculate recommended sysctl kernel parameter values for a given workload profile.
- Kernel Thread CalculatorCalculate the number of kernel threads spawned per CPU core for common kernel subsystems.
- Module Dependency CalculatorCalculate kernel module load order and dependency depth from modinfo dependency chains.
- Package Dependency CalculatorCalculate total download size and install order for a package and its dependency tree.
- Repository Mirror CalculatorCalculate storage and bandwidth needed to host a local mirror of a package repository.
- YUM DNF Cache CalculatorCalculate disk space consumed by the YUM or DNF package manager metadata and RPM cache.
- APT Cache CalculatorCalculate disk space consumed by the APT package cache and downloaded .deb archives.
- Package Size CalculatorEstimate installed size versus download size for a software package and its dependencies.
- Update Time EstimatorEstimate total time to download and install a batch of system package updates.
- Patch Window CalculatorCalculate the maintenance window duration needed to patch a fleet of servers safely.
- Reboot Duration CalculatorEstimate total server downtime from shutdown, POST, kernel boot and service startup phases.