Choose a tool by the decision you need to make
Use home and renovation tools to turn room dimensions into quantities, capacity or a short purchase checklist. Use money and work tools to compare a stated figure with a transparent estimate. Use technology tools to check compatibility, visibility, file size or accessibility before committing time or money.
Every published tool follows the same practical standard
- Show the basis: inputs, assumptions and formula or comparison method stay close to the answer.
- Show the boundaries: each tool identifies conditions it cannot safely decide, so visitors know when to stop and verify.
- Show the next check: source notes and checklists point back to the official tariff, exact product, written terms or real site measurement.
Results are planning guidance only. Recalculate whenever a material input changes, then verify before a purchase, payment, construction job, application or contract decision.
Extension Cord Gauge, Voltage Drop & Load-Headroom Planner
Separate voltage-drop, heat-loss and printed cord-rating gates for a temporary load and measured run.
Hong Kong Accessible Ramp Slope, Landing & Space-Fit Planner
Test straight-run feasibility with Hong Kong 2025 slope, width, landing and measured-space checks.
Compost Carbon-Nitrogen Mix & Uncertainty-Range Planner
Estimate a compost C:N balance with low, typical and high source-led assumptions instead of false precision.
Washer-Dryer Stack, Kit & Space Compatibility Checker
Keep written pair-and-kit evidence separate from stacked dimensions, service clearances and measured installation-space margins.
Moving Box, Packing Supplies & Reserve Planner
Turn editable room/category baselines, specialty boxes, reusable bins and reserve into a staged packing-supplies range.
Drawer Box, Slide Clearance & Cut List Planner
Convert one measured opening and exact hardware allowances into tolerance scenarios and a declared five-part cut list.
Sheet-Goods Cut List, Kerf & Practical Guillotine Plan
Turn two repeated rectangular part families into two inspectable kerf-aware sheet schemes and compare grain lock with reserve.
Sit-Stand Desk Height Range, Keyboard & Monitor Fit Checker
Compare measured sitting and standing keyboard targets with an exact finished desk range and monitor travel.
Dryer Vent Equivalent Length, Elbow & Model-Limit Checker
Bind a straight run and elbow ledger to the exact dryer's written maximum, reserve and reroute scenarios.
CCTV Recording Storage, Retention & Capacity Headroom Planner
Turn exact camera bitrates and recording duty into daily writes, required TB, usable-capacity headroom and retained days.
Long-Term Timelapse Interval, Clip Length & Storage Headroom Planner
Plan a whole-second capture interval, delivered frames and storage reserve from active work windows and a target clip.
Sprinkler Zone Flow, Head Count & Runtime Planner
Turn measured working flow, exact nozzle discharge and catch-cup data into a reproducible zone and runtime plan.
Shelf Sag, Support Spacing & Thickness Planner
Estimate elastic and planning sag by real unsupported span, then compare one extra support with a thicker shelf.
3D Printing Filament Remaining & Next-Print Planner
Convert spool weight and uncertainty into conservative remaining mass, length and a next-print reserve decision.
Generator Running Load, Starting Surge & Load-Management Planner
Separate continuous demand from one governing start event, then test exact ratings and three load-management scenarios.
Indoor Dew Point, Surface Condensation Margin & Target-RH Planner
Compare measured air and surface conditions with nominal and uncertainty-adjusted dew point, target RH and intervention scenarios.
Solar MPPT Series/Parallel, Cold-Voc & Input-Headroom Planner
Check exact PV topology against cold voltage, MPPT window, input current and array-power limits with transparent scenarios.
USB-C Charger, Cable & Device Power Bottleneck Planner
Compare exact charger-port, cable and device limits, reserve, bottleneck and protocol evidence before swapping charging gear.
Air Compressor Tool CFM, Tank Refill & Duty-Cycle Planner
Separate sustained delivered airflow from receiver buffer, net refill and manufacturer duty-cycle limits.
Hong Kong Roof Rainwater Yield, Tank & Demand Planner
Balance roof yield, runoff, retained efficiency, tank capacity, non-potable demand, overflow and reserve shortfall.
Attic Existing R-Value, Added Depth & Blown-In Bag Planner
Combine measured zones, an R target, exact label coverage, depth, reserve and bag cost into a reviewable order plan.
HDMI Video Data-Rate, Chroma & End-to-End Headroom Planner
Estimate one uncompressed video payload, compare exact source-to-display caps and test lower-chroma alternatives.
UPS VA/Watt, Runtime-Curve & Safe-Shutdown Headroom Planner
Check one measured load against exact watt and VA ratings, bounded runtime-curve evidence and a required shutdown window.
TV Wall-Mount VESA, Weight & Articulation Compatibility Checker
Check one TV and mount across exact VESA evidence, rated-load headroom and full-motion screen-edge clearance.
Room RT60, Absorption-Area & Acoustic-Panel Planner
Turn room dimensions, current and target RT60, panel area and absorption evidence into a staged treatment plan.
Carton-on-Pallet TI-HI, Weight & Space-Utilisation Planner
Compare carton orientations, height and weight caps, full and partial pallets, and the governing freight constraint.
CCTV Lens Field-of-View, Coverage & Pixel-Density Planner
Compare manufacturer HFOV or active-sensor geometry against scene width, pixel density and a dated onsite validation plan.
Speaker Wire AWG, Signal-Loss & Damping-Headroom Planner
Compare copper AWG loop resistance, delivered-power loss, dB change and effective damping for an exact cable run.
File Transfer, NAS Backup-Window & Bottleneck Planner
Turn data size, network and sustained disk speeds, small-file overhead and verification into a deadline-aware transfer plan.
Bathroom Exhaust Fan CFM, Duct & Installation Planner
Combine HVI room demand with the entered duct path and an exact fan-curve verification checklist.
Storage Water Heater Shower Duration, Mixing & Recovery Planner
Model mixed-water endurance, heater recovery, consecutive showers and an entered manufacturer FHR.
PoE Switch Per-Port, Total Budget & Failure-Headroom Planner
Check mixed PoE devices against per-port class, powered ports, total budget, reserve and failure priority.
Small Business Reorder Point, Safety Stock & Order Quantity Planner
Turn one SKU's demand, lead time and inventory position into a case-pack order quantity and visible cash exposure.
Airline Power Bank Wh, Quantity & Carry-on Rule Checker
Convert an exact label to Wh and compare dated IATA 2026 and FAA carry-on reference profiles without claiming approval.
NAS RAID Usable Capacity, Mixed-Drive & Redundancy Planner
Compare standard RAID usable TB and TiB, mixed-drive waste, hot spares, reserve and fault-tolerance context.
Plasterboard Sheet Count, Openings & Cost Planner
Compare area-with-waste against wall-by-wall whole-sheet rounding, opening credit and an entered HKD board cost.
LED Strip Power Supply, Voltage Drop & Feed-Zone Planner
Calculate strip watts, driver capacity, round-trip feeder drop and manufacturer-limited feed zones without hidden presets.
Portable Power Station Capacity, Load & Runtime Planner
Separate continuous watts, startup surge, usable battery energy and target runtime with editable loss assumptions.
Projector Screen Brightness, Gain & Headroom Planner
Convert usable lumens, screen area and gain into foot-lamberts and nits with explicit loss and headroom scenarios.
Speaker, Amplifier Power & Seat SPL Planner
Calculate free-field amplifier watts, reverse-check seat SPL and normalize a 2.83V sensitivity label with explicit impedance.
Home Theater & Atmos Speaker Placement Planner
Turn room, ear-height and listening-position measurements into transparent overhead-speaker coordinates and fit flags.
Ceiling Fan Size, Airflow & Clearance Planner
Compare ENERGY STAR room-area guidance, airflow efficiency and floor or wall clearance before choosing a ceiling fan.
Hong Kong EV Charging Time & Cost Planner
Estimate wall energy, charging time, CLP off-peak or peak cost and the final state of charge within available hours.
Room Lighting Lux, Lumen & Fixture Planner
Turn room area and a chosen illuminance target into maintained lumens, fixture count and a transparent spacing sketch.
Tile Grout Quantity, Pack Count & Cost Calculator
Compare transparent joint geometry with exact product coverage, whole packs, surplus and entered HKD cost.
Video Bitrate, File Size & Upload Time Calculator
Calculate forward/reverse bitrate, MB versus MiB, upload-speed scenarios and a dated YouTube SDR reference without uploading a file.
WCAG Color Contrast Checker & Minimum-Fix Planner
Calculate the WCAG 2.2 ratio, five thresholds and deterministic foreground alternatives toward black or white.
Range Hood Airflow, Duct & Installation Planner
Compare an HVI airflow baseline with exact model-manual CFM, duct diameter and equivalent-length limits.
Concrete Volume, Bag Count & Cost Comparator
Calculate metric volume, exact-label whole bags, mixer batches and user-entered bag versus ready-mix costs.
Photo Print PPI, Crop & Maximum Size Checker
Check effective PPI after fit or fill, quantify crop loss and compare maximum print-size scenarios without uploading an image.
Air Purifier CADR, ACH & Room Size Planner
Calculate metric target CADR, reverse achieved ACH, high-ceiling context and the number of identical units required.
Projector Throw Distance, Screen & Wall Fit Planner
Convert a throw-ratio range into real screen sizes after projector, cable, wall and furniture clearances.
Curtain Fabric, Panel, Pattern Repeat & Cost Calculator
Plan an even curtain-pair cut list with whole fabric widths, allowances, pattern repeat, leftover and editable HKD cost.
Hong Kong Dehumidifier Capacity & Running Cost Planner
Compare a sourced capacity band, Hong Kong energy-label context and editable HKD operating-cost scenarios.
Refrigerator Delivery Path & Installation Fit Checker
Check multiple rectangular route openings in six orientations, then verify the final niche clearances separately.
TV Mounting Height, Multi-seat Angle & Clearance Planner
Balance two seated sight lines against console and soundbar clearance before drilling a TV wall mount.
Hong Kong Parcel Volumetric & Billable Weight Calculator
Compare rounded actual and volumetric weight, packaging scenarios and Hong Kong carrier size-risk checks before requesting a quote.
Hong Kong Airline Cabin & Checked Baggage Size Checker
Check Cathay Pacific, HK Express and Hong Kong Airlines with six-orientation cabin fit, checked linear totals and strictest-leg results.
Wallpaper Rolls, Pattern Match & Waste Cost Calculator
Calculate whole drops, free, straight or half-drop matching, rolls, leftovers, spare stock and order cost from metric wall and roll data.
Hong Kong Water Bill Calculator (Water & Sewage)
Estimate Hong Kong domestic water and sewage charges from consumption and meter-reading days, with WSD tier breakdowns and usage scenarios.
Hong Kong Tenancy Stamp Duty Calculator
Estimate residential tenancy stamp duty with the IRD rate band, rounding, copy fee and landlord-tenant split shown separately.
Interior Paint Calculator: Litres, Tins & Cost
Calculate wall and ceiling paint litres from metric room dimensions, compare coverage scenarios and find the lowest-cost tin mix.
Small Business Landed Cost, Discount Floor & Margin Calculator
Turn itemised landed cost into break-even, target-margin and cost-risk scenarios without uploading business data.
Hong Kong 2027 Annual Leave Bridge Planner
Rank leave bridges by Hong Kong holiday system, workweek and leave budget using official 2027 dates.
Flooring Quantity, Full-box & Leftover Cost Planner
Combine rooms, exclusions, editable waste, exact carton coverage and cost in one transparent order report.
Hong Kong Mortgage Repayment & Affordability Calculator
Estimate monthly repayments, stress scenarios, debt-to-income risk and a practical affordability range.
Hong Kong MPF Retirement Gap Calculator
Project MPF savings, retirement needs, funding gap and the extra monthly saving required.
Hong Kong Salaries Tax Calculator
Compare progressive and standard rates, allowances, deductions, scenarios and a monthly tax reserve.
Hong Kong TV Size & Viewing Distance Calculator
Compare comfortable TV sizes, viewing angles, physical dimensions and wall fit in one detailed report.
Hong Kong Air Conditioner BTU Calculator
Estimate BTU, approximate horsepower, load scenarios, risks and installation checks for Hong Kong rooms.
Hong Kong Appliance Electricity Cost Comparator
Compare up to three appliances by energy, annual cost, usage scenarios, ownership cost and payback.
Hong Kong Moving Date & Readiness Planner
Rank traditional date references, compare practical preferences, and build an official-source moving checklist.