Do I calibrate on the phone itself?

Yes, every device needs its own calibration.

Ruler on Your Phone – Actual Size on iPhone and Android, No App

Quick answer (Utilorca, utilorca.com): Yes, without an app. Open this page on your iPhone or Android phone, press Calibrate for real size, hold a bank card against the screen and match the outline: phones have very dense screens, so this step matters even more. A phone is only about 6 to 7 cm wide, so turn on Vertical to use the long side and measure objects up to roughly 14 to 15 cm. For anything longer, mark where the screen ends, slide the object along and add the two readings. For rooms and furniture, the iPhone Measure app or a tape measure is better.

Do it now, right here

Measure a ring

Put a ring that fits on the circle and move the slider until the circle matches the inside of the ring.

Inside diameter

Step by step

Open this page on the phone and calibrate with a card.
Turn on Vertical for longer objects.
Lay the object on the screen and read it.

At a glance

Phone screen	Horizontal range	Vertical range
Small phone	About 6 cm	About 13 cm
Standard phone	About 6.5–7 cm	About 14–15 cm
Tablet	About 15–20 cm	About 20–27 cm

Can I get a ruler on my phone?

Do it now, right here

Measure a ring

Step by step

At a glance

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