Pixel 4a Ruler
Actual size, on screen

What fits on the Pixel 4a screen – and what doesn't

• an index card (long side, 3×5)127 mm / 5.00 infits in one go (6.8 mm to spare)
• a 4×6 photo (short side)101.6 mm / 4.00 infits in one go (32.2 mm to spare)
• a playing card (long side)88.9 mm / 3.50 infits in one go (44.9 mm to spare)
• a CD case (long side)142 mm / 5.59 in8.2 mm too long – measure in 2 passes
• a 4×6 photo (long side)152.4 mm / 6.00 in18.6 mm too long – measure in 2 passes
• a US dollar bill (long side)155.96 mm / 6.14 in22.1 mm too long – measure in 2 passes

The Pixel 4a screen in numbers

• The screen is 133.8 mm (5.27 in) tall – 5.5 quarters laid end to end
• 1.56 times the long side of a credit card (85.6 mm)
• There are 175 physical pixels in every centimetre, 444 in every inch
• The finest 1 mm tick is 17.5 pixels apart

Compared with nearby models

Screen height compared with the Pixel 4a (61.8 × 133.8 mm).

• Pixel 52020 · 63.8 × 138.3 mm4.5 mm taller
• Pixel 62021 · 66.7 × 148.3 mm14.5 mm taller

How this ruler stays true to size

The Pixel 4a packs 444 pixels into every inch and draws 2.775 physical pixels per CSS pixel, so one millimetre is 6.30 CSS px. The ticks are rebuilt from that number and the live pixel ratio each time the page opens, which is why no calibration is needed on this model. The right side of the strip is metric (mm/cm) and the left side is inches in 1/16 steps; 1 inch = 25.4 mm.

If the ticks look off (display zoom or font-size settings change the ratio), hold a credit card against the screen – its long side is 85.6 mm – and use the card calibration. The calibration tool and the full device list are in Japanese, but the controls are simple: pick card or coin, drag to match. 日本語版はこちら.