Launched this week
Online Ruler
Actual Size Online Ruler
2 followers
Actual Size Online Ruler
2 followers
Free online ruler and accurate virtual ruler tool to measure physical objects at true 1:1 actual size on your screen in inches, centimeters, and millimeters.
Launch Team
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Promoted
Hey Product Hunt! 👋 I'm Gourav.
I built Online Ruler because I kept needing to measure small things—like screws, watch bands, or coins—and never had a ruler handy. Most online rulers fail on phones because mobile screens have such high pixel density.
To fix that, you just hold any card from your wallet against the screen to calibrate it in seconds (since all cards are standard 85.6 mm). Then just lay your phone flat and measure items directly on your display in cm, mm, or inches—no app install or sign-up needed.
Would love for you to try it on your phone with a card. Did it line up accurately on your device? 🚀