Printables that measure correctly
Measuring tools you can print at home, drawn as real vector geometry in millimetres. Each one carries a 50 mm calibration bar, so you can check in two seconds that your printer did not shrink the page.
Printable ruler
A ruler is only useful if it is accurate, and most printable ones are not, because the print dialog quietly resizes them.
Measuring when no ruler is to hand · Checking a parcel or screen size · School geometry
Printable ring sizer
Two ways to find a ring size at home.
Buying a ring as a surprise · Online jewellery orders · Resizing an heirloom
Printable protractor
A protractor printed at true scale, marked every degree with labels every ten, in either the usual semicircle or a full 360° circle.
Homework and geometry · Woodworking and mitre angles · Sewing and quilting
Graph paper
Square, dot, isometric, hexagonal and ruled sheets in any grid size, on A4 or Letter.
10 ready-made sheets · build your own
Why these print correctly
Most printable tools are images, and an image only becomes a physical size when something decides how many pixels go in an inch. Print dialogs then add their own scaling on top. The result measures a few percent short, which is useless for a ruler and worse for a ring.
These sheets are vector PDFs with the geometry specified in millimetres. Print at 100% and a 50 mm bar measures 50 mm. If it does not, scaling is switched on somewhere — our printing guide lists the setting to change in every common program.