Developer Tools
Screen Size Calculator
Screen Size Calculator is a browser-based calculator tool on CalcToolsBase. Free, browser-based Screen Size Calculator. Enter your input for an instant, clearly-labelled result - no signup, no uploads. To use it, enter your values and view the result directly in your browser — no signup and nothing to install.
Give Screen Size Calculator your diagonal size and aspect ratio and it returns the width, height and area straight away. Built to find a screen’s physical size, it runs entirely on your device.
Browser-side developer and utility helpers for everyday and learning use. Everything runs locally in your browser and nothing you enter is uploaded. Validate production or security-critical output with trusted, official tools before relying on it.
About this tool
The Screen Size Calculator is a lightweight, browser-based calculator for when you need to find a screen’s physical size. It takes your diagonal size and aspect ratio, applies the diagonal and aspect ratio via Pythagoras, and reports the width, height and area clearly. Nothing is uploaded and nothing is saved between visits.
How to use
- Enter the screen diagonal in inches.
- Choose the aspect ratio from the menu.
- Run the calculator to split the diagonal.
- Read the width, height, and area.
Why use the Screen Size Calculator
Instant
Each result is computed on your device the moment you run the tool.
Private
The text and numbers you enter stay in your browser and are never uploaded.
Free
No signup and no paywall to use any tool in this set.
Works offline
Once the page has loaded it keeps working on a weak or dropped connection.
Built for developers
Plain inputs and outputs you can copy straight into code, configs, or notes.
Honest by design
Conversions and heuristics are for everyday and learning use; verify security-critical output with trusted, official tools.
Common uses
Screen Size when working out width and height from a diagonal
Screen Size when checking a screen fits a space
Screen Size for picking a phone or laptop screen
Screen Size for a home-theatre viewing-distance plan
Screen Size for a gaming-setup decision
Screen Size when planning a wall mount or desk
Technical notes
Screen Size Calculator derives screen width, height and area from the diagonal and aspect ratio using the Pythagorean theorem.
Results are reference values; validate against your own environment before relying on them in production.
Results are rounded for display; the underlying calculation keeps full precision.
Worked example
A 16:9 screen with a 27-inch diagonal is about 23.53 in wide and 13.24 in tall.
FAQ
How are width and height derived from the diagonal?
The diagonal is split using the aspect ratio, so width is the diagonal times the ratio width divided by the diagonal of the ratio rectangle, and likewise for height.
Why do two screens with the same diagonal differ in width?
Different aspect ratios distribute the same diagonal differently, so a wider ratio gives more width and less height.
What units does it report?
Width and height are given in inches and the area in square inches, based on the diagonal you enter.
How does this relate to the pixel density tool?
This tool gives physical dimensions, while the pixel density tool uses resolution and diagonal to report sharpness.