About RulerInches

RulerInches was built because every other online ruler we tested was inaccurate. Most online rulers assume 96 PPI for every screen — wrong.

• We built a database of 200+ devices with exact PPI values.
• Result: a ruler that is accurate within 1mm on most devices.
• 100% free, no account needed, no downloads.
• Works on iPhone, Android, Windows, Mac.
• Built with privacy first — zero data collection.