MeasureSpark

Screen & ruler

Screen Measurement Tools

Measure an object on your display, calculate screen density, or turn a diagonal size into usable width. These tools are designed for quick checks on phones, monitors, and TVs.

Choose a calculator

Open a tool, enter your measurements, and get an answer without an account.

Actual Size Online RulerCalibrate your screen and use a real-size online ruler in inches, centimeters, and millimeters.Screen PPI CalculatorCalculate screen pixel density from resolution and diagonal size.Screen Size CalculatorCalculate TV or monitor width and height from diagonal size and aspect ratio. A 55-inch 16:9 screen is about 47.9 inches wide.

Choose the right screen measurement tool

Start with the online ruler when the job is to compare a small object directly against the display. Calibrate it on the same screen you will use, keep browser zoom at 100%, and switch to a physical measuring tool when accuracy affects safety, fit, or cost.

Use a calculation instead when you know specifications rather than a physical length. Resolution plus diagonal size determines pixel density; diagonal plus aspect ratio determines viewable width; pixel count plus a known PPI determines physical output size.

Online rulerMeasure a small object against a calibrated display.Screen PPI calculatorFind pixel density from native resolution and diagonal size.Screen size calculatorEstimate viewable panel width before checking exact product dimensions.