$ ./geek-tools

A compact library of practical infrastructure, cloud, networking, storage and resilience tools. Open only the calculator you need; search or filter the library when you know roughly what you are looking for. Calculator inputs stay in your browser. Tools marked as live checks, lookups or analysers send only the hostname, domain, IP or MAC value needed to perform the requested lookup; pasted email headers remain local.

36 tools
NETWORKING

Network & IP tools

Latency, transfer-time and IPv4 planning without reaching for a spreadsheet.

ASSESSMENTAzure Region Pulse AssessmentMeasure first. Place workloads smarter. Assess Azure regions using real network measurements, workload requirements, resilience, service fit, residency, live pricing and deployment readiness. Compare candidate regions, identify primary and DR recommendations, model multi-site placement and produce a client-ready assessment report.
CALCULATORData transfer timeEstimate how long a backup, migration or upload will take at a given sustained line rate.

Runs locally in your browser

CALCULATORIPv4 CIDR calculatorSee network/broadcast addresses, usable range and host count, including point-to-point /31 and host /32 semantics.

Runs locally in your browser

CALCULATORIPv4 subnet plannerSplit a parent IPv4 network into right-sized VLSM subnets from a list of required usable host counts.

Runs locally in your browser

STORAGE & HCI

Capacity, HCI & storage performance

Plan protected capacity, rebuild headroom and storage performance without hiding the assumptions.

CALCULATORRAID usable capacityA quick RAID 0/1/5/6/10 capacity estimate before filesystem, metadata and vendor-reserve overheads.

Runs locally in your browser

CALCULATORCeph usable capacityEstimate raw, theoretical and recommended usable capacity for replicated or erasure-coded Ceph storage.

Runs locally in your browser

CALCULATORNutanix capacity & resiliencyEstimate RF2/RF3 logical capacity, node-failure rebuild reserve, operating headroom and optional data-reduction effect for a homogeneous cluster.

Estimator only: production Nutanix designs should be validated with Nutanix sizing guidance, workload data and the actual node/storage configuration.

Runs locally in your browser

CALCULATORStorage growth forecastProject capacity growth and calculate how much provisioned capacity is needed to preserve operational headroom.

Runs locally in your browser

CALCULATORDisk rebuild timeEstimate rebuild duration from drive size, sequential throughput and the share of that throughput available while production workloads continue.

Runs locally in your browser

CALCULATORIOPS / throughput / queue depthTranslate IOPS and block size into throughput, split a read/write workload and estimate outstanding I/O from latency.

Runs locally in your browser

BACKUP & DR

Backup, immutability & disaster recovery

Estimate repository requirements, recovery objectives and the network capacity behind them.

CALCULATORBackup window / throughputWork out the sustained throughput needed to protect the expected changed data inside a target backup window.

Runs locally in your browser

CALCULATORBackup repository estimateEstimate repository capacity from a full dataset, daily change rate and retention period, with data-reduction and headroom assumptions.

Runs locally in your browser

CALCULATORVeeam / immutable repository estimatorModel retention plus immutability, daily change, data reduction and the extra capacity impact of conventional active fulls versus block-cloned synthetic fulls.

Sizing is deliberately conservative and simplified; actual Veeam chain behaviour, fast-clone support, retention transforms and workload compressibility can change consumption.

Runs locally in your browser

CALCULATORRPO / RTO impactTurn recovery objectives into the maximum data-loss window and outage window they actually imply.

Runs locally in your browser

CALCULATORDR replication bandwidthEstimate the sustained WAN bandwidth needed to keep pace with change data and show how much data is generated inside each RPO interval.

Runs locally in your browser

VIRTUALISATION & EUC

Virtualisation, HA & user compute

First-pass capacity planning for hypervisor clusters and Azure Virtual Desktop host pools.

CALCULATORVirtualisation vCPU capacityA deliberately simple cluster compute planner based on physical cores, HA reserve and a chosen vCPU:pCore consolidation ratio.

Runs locally in your browser

CALCULATORVMware / vSphere HA capacityEstimate CPU and memory capacity left after host-failure reserve and an operational utilisation ceiling, with a transparent vCPU:pCore assumption.

This models homogeneous hosts and percentage-style reserve. VM reservations, NUMA, DRS, admission-control policy and workload peaks can be more restrictive.

Runs locally in your browser

CALCULATORAzure Virtual Desktop host pool sizerEstimate the number of session hosts from peak concurrency, per-user CPU/RAM assumptions, host size, target utilisation and spare-host policy.

Use measured workload data where possible. Login storms, application behaviour, GPU needs, profile storage and autoscale policy can materially change the correct host count.

Runs locally in your browser

AVAILABILITY & FACILITIES

Availability, power & facilities

Turn uptime, electrical and cooling assumptions into numbers you can use for first-pass planning.

CALCULATORSLA downtime allowanceConvert an availability percentage into the maximum downtime implied over a day, week, 30-day month or year.

Runs locally in your browser

CALCULATORServer power costEstimate annual energy use and electricity cost from device count, measured/assumed wattage and operating hours.

Runs locally in your browser

CALCULATORRack power & coolingTranslate rack IT load into facility power, current draw, cooling load, annual energy and electricity cost.

Runs locally in your browser

CALCULATORUPS runtime estimatorApproximate runtime from usable battery energy, load, inverter efficiency and an allowance for battery ageing.

Real UPS runtime is non-linear and vendor load curves are more accurate; use this for rough planning only.

Runs locally in your browser

SECURITY & DNS

Security, DNS & Microsoft

Domain, email, web-security and Microsoft checks for day-to-day troubleshooting.

LIVE CHECKDomain security health checkCheck mail, DNS and common domain-security signals in one pass.

Performs an external lookup

ANALYSERSPF analyser & lookup counterFollow SPF includes recursively and expose DNS lookup-limit risk.

Performs an external lookup

ANALYSERDMARC analyserTranslate a domain DMARC policy into readable enforcement and monitoring information.

Performs an external lookup

LOOKUPDNS lookupInspect A, AAAA, MX, TXT, NS and CAA records from one place.

Performs an external lookup

LIVE CHECKSSL/TLS & certificate checkerConfirm that a hostname completes a trusted HTTPS/TLS connection.

Performs an external lookup

LIVE CHECKHTTP security header checkerInspect common browser security headers returned by an HTTPS site.

Performs an external lookup

CALCULATOREmail header analyserPaste message headers and extract authentication results, Received hops and obvious delivery clues locally in your browser.

Headers stay in your browser.

Runs locally in your browser

LOOKUPDNS propagation checkerCompare DNS visibility and help diagnose resolver/cache differences.

Performs an external lookup

LOOKUPIP / ASN lookupResolve an IP or hostname and show reverse-DNS information for network troubleshooting.

Performs an external lookup

LOOKUPMAC / OUI lookupNormalise a MAC address, identify its OUI and detect locally administered addresses.

Performs an external lookup

LIVE CHECKMicrosoft 365 domain healthCheck Microsoft 365 mail routing, SPF, DMARC, Autodiscover and common DKIM selector records.

Performs an external lookup

LIVE CHECKExternal website security assessmentRun a safe, non-destructive assessment of the public web security posture exposed by a hostname.

Passive assessment only: no exploitation, brute force, port scanning or vulnerability exploitation.

Performs an external lookup

LIVE CHECKWordPress security exposure checkCheck common public WordPress hardening signals and exposed endpoints without attempting exploitation.

Checks a small fixed set of public WordPress endpoints only; it is not a penetration test.

Performs an external lookup

CALCULATORWindows lifecycle checkerQuickly identify common Windows client and Server lifecycle milestones from a maintained local reference table.

Always verify lifecycle dates against Microsoft Lifecycle documentation before making support decisions.

Runs locally in your browser

Planning estimates, not vendor sizing

These calculators deliberately show their assumptions. Production results can be affected by workload behaviour, metadata and filesystem overheads, compression/deduplication, failure-domain design, reservations, protocol efficiency, storage-controller behaviour and vendor-specific implementation. Use the results as a first-pass planning aid, then validate important designs with measured workload data and the relevant vendor sizing guidance.