Online ruler

A ruler at actual size on any screen. Match a bank card to the outline once, then measure anything small.

2⅞in

7.3 cm · 73 mm

Not calibrated yet · standard screen size

How to use it

  1. Hold a bank card against the screen and match the outline.
  2. Put the thing you are measuring on the ruler, against the 0.
  3. Read the yellow line, in inches and fractions.

This page, or the app?

This pageTapepal on iPhone
LengthUp to the width of your screenAnything your camera can see
SetupMatch a bank card firstPoint and tap
SavedGone when you close the tabSaved with the photo

Questions

Why do I need a bank card?

Screens have different pixel sizes. A bank card is always 3⅜ in wide, so matching it tells the page how big an inch is on your screen.

Is it accurate?

Once calibrated, to about 1/16 in on most screens.

Does it work on a phone?

Yes, but a phone screen is short. For longer things, use the camera.

Guides that use it

More free tools

Too big for the screen?Tapepal on the App StoreGet