Use a free online ruler to measure objects on your screen. Displays accurately in centimeters and inches. Ideal for measuring cards, phones, A4 paper, and more.

Online Ruler – Precise Measurement in cm & Inches

Need to measure a card, phone, or A4 paper but don’t have a ruler handy? This online ruler lets you accurately measure directly on your screen in centimeters or inches.

Main Features

📏 Horizontal & vertical ruler: measure width and height
🔁 Switch between cm & inches: supports both units
🖥️ Screen calibration: accurate to your device’s DPI
📱 Works on all devices: PC, laptop, tablet, mobile
🆓 100% free: no installation or registration

How to Use

Place the object on your screen (e.g. card, phone)
Align it with the ruler scale
Adjust the scale if needed
Read the size directly from the screen

What Can You Measure?

📇 Credit cards, ID cards
📱 Phones, tablets
📄 A4 paper, documents
📦 Boxes, packages
🧰 Small tools, accessories

Why Use This Tool?

❌ No installation needed
✅ Quick and easy to use
🔒 No personal data collected
🌐 Works in any browser

Start Now

👉 Open the online ruler and start measuring now!