UD5 Toolkit
Logical Sizing Properties Demo - Online block‑size & inline‑size
Compare width/height with block‑size/inline‑size in different writing modes. Understand intrinsic sizing. Copy best practices.
Shipping Box Size Optimizer - Online Fit Items into Carton
Carton Dimensions (inner)
cm
cm
cm
Items to Pack
Max 30 items; allowed rotation: all 6 orientations.
Frequently Asked Questions
It calculates the optimal placement of rectangular items into a shipping carton, considering all possible rotations, to maximize space utilization and minimize unused volume. You input carton inner dimensions and item dimensions, and it provides a visual packing plan and utilization metrics.
We use a heuristic (greedy with maximal spaces) that produces high-quality results for most practical cases. It is not guaranteed to find the perfect global optimum, but it outperforms simple volume-comparison tools and works reliably for up to 30 items.
Yes, the optimizer automatically considers all 90-degree rotations (length, width, height permutations) for each item to find the best fit.
Utilization % = (total volume of placed items / carton inner volume) Ă— 100. It reflects how efficiently the carton volume is used.
Currently this tool handles only rectangular boxes. Weight distribution and irregular shapes are not supported.
3D Packing Visualization
Drag to rotate (placeholder)
Enter carton and items, then click Optimize Packing.
Backpack Weight Planner – Online Distribute Load & Reduce kg
List each item with weight, see total load. Color-coded recommendations for reducing pack weight. Local storage.
size‑container Demo - Online Intrinsic & Styled Queries
Explore the size‑container and inline‑size CSS properties for container queries. Understand containment contexts. Visual guide.
Element Resize Detector - Online Monitor Size Changes
Select any element on the test page and monitor its size changes with ResizeObserver. See log of all entries.
Photo Print Size Guide - Online Aspect Ratio to Dimensions
Enter image pixel dimensions and compute maximum print size at various DPI. With aspect ratio presets (4x6, 5x7, 8x10) and cropping preview. Local tool.
Crochet Hat Sizing Guide – Online Measure & Increase
Enter head circumference to get crown diameter and length. Perfect fit top‑down hats.
Tire Size Visualizer - Online Compare & Dimensions
Enter two tire sizes and see a side‑by‑side comparison of diameter, width, and speedometer error. Local math.
Rubber Band Ball Calculator – Online Estimate Bands Needed
Enter current ball size and target to find approx rubber bands required. Fun and satisfying.
Photo Print Resolution Checker – Online DPI Maximum Size
Enter megapixels and desired DPI to see the maximum print size without upscaling. Quick quality check.
Portable Generator Sizing – Online Wattage Estimator
Add appliances with running and starting watts to estimate needed generator capacity. Prevent overload.
Diaper Size Finder - Online Weight-Based Size Guide
Enter baby's weight in lbs or kg to see suggested diaper sizes across major brands. General reference, no data collected.
Resize Observer Playground - Online Watch Element Size
Drag to resize a box and see the Resize Observer callback fire. Get contentRect and borderBoxSize. Learn the API.
Bird Toy Safety Checker – Online Materials & Size Guide
Select bird species and toy type to see potential hazards and size recommendations.
Surfboard Volume Estimator – Online Dimensions to Liters
Enter length, width, thickness to approximate surfboard volume. Compare to your ideal volume based on weight.
Print Readability Calculator – Online Minimum Font for Distance
Enter viewing distance to get the minimum readable print font size. Design posters and signs.
Megapixel Calculator - Online Print Size & Resolution
Find out how large you can print based on image resolution in pixels. Understand DPI and megapixels.
3D Print Filament Calculator - Online Weight, Cost & Length Tool
Estimate filament usage: enter weight or length and get the remaining value plus cost. PLA/ABS density reference. Local calculation.
Felting Shrink Calculator – Online Predict Wool Felted Size
Knit a swatch, measure before and after felting, and let this tool calculate the shrink percentage. Plan your felted projects accurately.
Spray Foam Insulation Calculator – Online Board Feet
Estimate board feet of spray foam needed for a cavity. Compare closed‑cell and open‑cell.
CSS resize Property Demo - Online User‑Resizable Element
Make an element resizable horizontally, vertically, or both. See the handle and code. Useful for textareas.
Print CSS Generator - Online Optimize Pages for Paper
Toggle print‑specific styles like removing backgrounds, showing link URLs, and adding page breaks. Generate a complete print stylesheet instantly.
Font Size Scale Preview - Online Typography Visualizer
Type a few words and see them rendered at every heading size (h1–h6) with your chosen font. Perfect for design systems.
Body Fat Percentage Estimator - Online US Navy & Covert Bailey Method
Estimate body fat percentage using neck, waist, hip (if female) measurements. Supports US Navy, Covert Bailey, and 3-site skinfold methods. No data sent to server.
scroll‑padding & scroll‑margin Demo - Online Anchor Position
See how scroll‑padding and scroll‑margin affect the position of elements when using anchor links or scroll‑snap. Visual.
Print CSS Generator - Online Optimize Page for Paper
Add print styles like removing backgrounds, adding page breaks, setting margins. See print preview instantly.
Pregnancy Week by Week Size – Online Fruit Comparison
Enter gestational week to see baby's approximate size compared to a fruit/veg. Visual fun.
Virtual Stud Finder Trainer – Online Learn Wall Framing Spacing
Interactive guide to understanding standard 16/24 inch stud spacing. Visualize wall internals. Useful before drilling.
Image vs. SVG Weight Comparator - Online Byte‑for‑Byte
Paste a raster image and an SVG, see the file size and rendering time. Understand when to use vector. Local.
Ideal Weight Range Calculator - Online Hamwi, Devine & Robinson Methods
Find your healthy weight range using multiple medical formulas (Hamwi, Devine, Robinson, Miller). Frame size adjustment included. Instant local computation.
Depth of Field Calculator – Online Near/Far Focus Limit
Input camera sensor, focal length, aperture, distance to get hyperfocal distance and DoF range. Visual chart.