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Scale & big-number visualiser

Sizewise

Make sizes, amounts and big numbers feel real: to-scale lineups, fit counts and stacks.

Launch Sizewise → Tutorials

Sizewise turns numbers people cannot picture into things they can see. Line up 337 objects from atoms to galaxies at true scale, count how many of one thing fit in another, stack money as banknotes, explain any big number and see a life in weeks or a rate ticking by. Every object size comes from a cited Wikidata statement, and every view runs the same engine as the API and MCP tools.

Free · runs in your browser · no sign-up · Version 1.0.0

Sizewise lineup view with skyscrapers and towers drawn side by side at one scale, a zoom slider and an object list

Screenshots

Features

  • True-scale lineups

    Up to 24 objects side by side on one ground line, with a log-zoom slider from atoms to galaxies and your own objects such as “Me = 1.8 m”.

  • Pairs for huge ranges

    When sizes differ by trillions, each neighbour pair is drawn at its own scale with the factor between them.

  • Sourced object library

    337 objects in 13 groups, each with its Wikidata item, property and value, so every size can be checked.

  • How many fit

    Counts by length, area or volume, with the real gaps between spheres, or packs whole boxes in layers with a floor plan.

  • Money as cash

    An amount as US dollar or euro notes: how many, how high, how heavy and how many EUR-pallets.

  • Big-number explainer

    Digits, scientific notation, short- and long-scale names up to 10^3002, counting time and the famous numbers nearby.

  • Life in weeks

    One row per year and one box per week, with your milestones and exact counts of days, Sundays and leap days.

  • Rate counters

    Turn “so much per year” into per second, watch it count live and copy a self-contained counter for your own page.

  • Exports

    SVG and PNG drawings, CSV tables, the embed snippet and print-ready pages for class or an article.

  • Private and local

    Projects autosave in this browser with recent files, undo and redo, project files and share links that leave out birth dates.

  • API and MCP tools

    Six tools give AI agents and scripts the same lineups, fit counts, cash stacks, number names, week grids and rates.

  • Keyboard first

    Number keys switch views, + and − zoom the lineup, Ctrl+Z undoes, and single-key shortcuts can be switched off.

Templates

Start from a ready-made project and change it to fit.

Built-in tools

Sizewise uses these tools. Each one also has its own page and works on its own, in the browser, through the JSON API and through MCP.

  • Sizewise Scale Comparison Sizewise engineLine up buildings, animals, planets or atoms side by side, drawn to true scale.
  • Sizewise How Many Fit Sizewise engineHow many Earths fit in the Sun, golf balls in a room or pallets in a trailer?
  • Sizewise Big Number Explainer Sizewise engineWhat does a googol, 2^64 or 8 billion really mean? Names, digits and counting time.
  • Sizewise Money Stack Sizewise engineHow tall is a million dollars? Banknotes as a stack, by weight and on pallets.
  • Sizewise Life in Weeks Sizewise engineYour life as a grid of weeks: one row per year, with milestones and exact counts.
  • Sizewise Rate Counter Sizewise engineTurn “so much per year” into per second, project it, and embed a live counter.
  • UnitProof Unit CalculatorUnit maths you can audit: dimension check, exact factors and a full derivation tree.

For AI agents

Sizewise runs on a deterministic engine. The same functions are available as tools with a JSON API and MCP, so scripts and AI agents get exactly the results the app shows.

  • Sizewise Scale Comparison – Line up buildings, animals, planets or atoms side by side, drawn to true scale.
    Tool page · POST https://sizewise.usefulweb.app/api/v1/tools/sizewise-scale-compare/calculate · MCP sizewise_scale_compare
  • Sizewise How Many Fit – How many Earths fit in the Sun, golf balls in a room or pallets in a trailer?
    Tool page · POST https://sizewise.usefulweb.app/api/v1/tools/sizewise-fit-count/calculate · MCP sizewise_fit_count
  • Sizewise Big Number Explainer – What does a googol, 2^64 or 8 billion really mean? Names, digits and counting time.
    Tool page · POST https://sizewise.usefulweb.app/api/v1/tools/sizewise-big-number/calculate · MCP sizewise_big_number
  • Sizewise Money Stack – How tall is a million dollars? Banknotes as a stack, by weight and on pallets.
    Tool page · POST https://sizewise.usefulweb.app/api/v1/tools/sizewise-money-stack/calculate · MCP sizewise_money_stack
  • Sizewise Life in Weeks – Your life as a grid of weeks: one row per year, with milestones and exact counts.
    Tool page · POST https://sizewise.usefulweb.app/api/v1/tools/sizewise-life-weeks/calculate · MCP sizewise_life_weeks
  • Sizewise Rate Counter – Turn “so much per year” into per second, project it, and embed a live counter.
    Tool page · POST https://sizewise.usefulweb.app/api/v1/tools/sizewise-rate-counter/calculate · MCP sizewise_rate_counter
  • UnitProof Unit Calculator – Unit maths you can audit: dimension check, exact factors and a full derivation tree.
    Tool page · POST https://sizewise.usefulweb.app/api/v1/tools/unitproof/calculate · MCP unitproof

Build a project through the API, then open it in the app with a link to https://sizewise.usefulweb.app/app#project=<base64url JSON>.

Import & export

Import

  • Sizewise project (.sizewise.json)
  • Share link (#project=)
  • Your own objects as “Name = 1.8 m” or “Name = 40 × 30 × 20 cm”

Export

  • Sizewise project (.sizewise.json)
  • Lineup, fit plan, money stack and week grid as SVG and PNG
  • Lineup and number tables as CSV
  • Live counter as an HTML snippet
  • Print view
  • Share link

Keyboard shortcuts

Keyboard shortcuts in Sizewise
KeysAction
1 … 6Switch between Lineup, Fit, Money, Numbers, Life in weeks and Rate
+ / −Zoom the lineup in or out (one step is a factor of about 3)
0Fit the lineup to the largest object
Ctrl + ZUndo
Ctrl + Shift + ZRedo
Ctrl + SSave project file
Ctrl + OOpen project file
?Show keyboard shortcuts (single-key shortcuts can be switched off there)

Frequently asked questions

Where do the sizes come from?

From Wikidata, the free knowledge base (CC0). Each of the 337 objects names its Wikidata item, the property (for example height or diameter) and the value as stated there, so you can open the item and check it.

Why is a dinosaur or a whale shorter or longer than I remember?

Animal sizes vary between individuals and between estimates. Wikidata often records a typical or a maximum length; Sizewise shows exactly that statement and does not mix sources.

Are the silhouettes accurate?

Only the measured dimension is to scale. The shapes are simple drawings made for Sizewise; their other side comes from the object’s own second dimension when Wikidata has one, else from typical proportions.

Why can I not see the smallest objects?

At one true scale, an atom next to a skyscraper is far smaller than a pixel. Zoom in with the slider or the + key, or switch to the pairs drawing, which shows each neighbour pair at its own scale.

How are “how many fit” answers counted?

By pure ratios of length, area or volume, optionally with the gaps real spheres leave (74 % at best, about 64 % when poured), or as whole boxes in layers with rows in up to two orientations. The box count is a guaranteed minimum; clever mixed patterns can sometimes fit a few more.

How thick is a euro note?

The European Central Bank publishes the sizes of euro notes but no thickness or mass. Sizewise asks you for those values (0.11 mm by default) and marks them as assumptions. US notes use the Bureau of Engraving and Printing’s figures.

Is my birth date stored or shared?

Only in this browser’s storage and in project files you save yourself. Share links never contain the birth date, milestones or notes.

Can I put the live counter on my own website?

Yes. The Rate view writes a small piece of HTML with its own script. It counts from the moment a visitor opens the page, sends nothing anywhere and slows down for people who prefer reduced motion.

Limitations

What Sizewise does not do (yet):

  • Many common animals, from cats to elephants, have no size in Wikidata yet, so they are not in the list; add them as your own objects.
  • Each object has one size. Objects with a second or third dimension in Wikidata use it for the drawing and for area or volume; the others are drawn with typical proportions.
  • Mountains are measured by their summit elevation above sea level, not their height above the surrounding land (except Mauna Kea from its base).
  • Box packing tries rows in two orientations per layer; it does not search irregular mixed patterns.
  • Big numbers are exact up to 20 000 digits; larger ones keep only their logarithm. Names are given in English.
  • Rates are constant: no growth, seasons or time-of-day patterns.

Tutorials

Learn Sizewise step by step.

  1. Your first lineup in five minutesPut skyscrapers, animals and yourself side by side at one true scale, zoom from the tallest object down to the smallest and check every size at its source.Beginner 5 min
  2. From an atom to the observable universeCompare sizes that differ by more than 36 orders of magnitude with the pairs drawing, and learn how Sizewise reads Wikidata sizes for atoms, planets and galaxies.Beginner 6 min
  3. How many fit — Earths, balls and palletsCount how many objects fit into another by length, area or volume, with the gaps that real spheres leave, or as whole boxes packed in layers with a floor plan.Intermediate 7 min
  4. One million dollars in cashSee an amount of money as real banknotes — how many notes, how high the stack is, how much it weighs, how much floor it covers and how many EUR-pallets it fills.Beginner 5 min
  5. Big numbers made tangibleRead any big number aloud in the short and long scale, see all its digits, how long counting to it would take and which famous numbers lie nearby.Beginner 5 min
  6. Life in weeks and live countersDraw your life as a grid of weeks with milestones, count days, Sundays and Full Moons, and turn any rate into a live counter you can put on your own web page.Beginner 6 min

Ready to try it?

Launch Sizewise →

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