12 tools · same engine
Tools
The converter answers one question at a time. These answer the ones that come in batches — a column of measurements, a table for a drawing, a reference card for the wall, a widget for someone else's page.
- Spin the wheel Make a decision with 60 customizable wheels. Pick names, choose dinner, play games, set weights, eliminate winners and share your own wheel.
- Personal dashboard Build a private home screen from quick conversions, favourites and recent calculators. Export or restore it as JSON.
- Conversion workspace Keep up to 100 live conversions and notes together, with reorder, duplicate, undo, redo and a self-contained share link.
- Measurement log Capture dated values, add tags and notes, re-express them in compatible units, and export CSV or portable JSON.
- Range & tolerance converter Convert both ends of a range or a value with plus/minus tolerance while keeping the complete interval visible.
- Offline library Choose converter categories, calculator groups and everyday packs to keep on this device without a connection.
- Batch converter Paste a column of numbers — or a column of numbers with their own units — and get a column back. Copy it as a Markdown table or download it as CSV.
- Conversion table builder Pick two units, a starting value, a step and a row count, and build exactly the table you need. Shareable by URL, exportable as CSV, Markdown or HTML.
- Compare every unit One value shown in every unit of a category at once, sortable by size or name, so you can see where a quantity sits across systems.
- Printable cheat sheets A one-page reference card per category: the conversions worth memorising, sized for paper and printed in black on white.
- Embed a converter Put a working converter on your own page with one <iframe>. Choose the category and starting units, then copy the code.
- Saved & recent Everything you have starred and the conversions and calculators you used last — held in this browser and nowhere else.
Why these run in your browser
Every tool here does its arithmetic on the page, with the same exact-rational engine the rest of the site uses. Nothing you paste into the batch converter is sent anywhere, and none of them need a network connection once the page has loaded.
They read your display settings too — significant figures, notation, thousands separators and decimal mark — so a table exported from here matches what you see on a converter page. How the maths works →