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Viewport Size Calculator

Convert px to vw/vh. Viewport units. For responsive design. Assumes 1920x1080. Free design tool with instant browser-based results — no account, works on

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Projects using Viewport Size Calculator

This tool is part of these guided projects. Each project provides step-by-step instructions with checklists and all the tools you need in one place.

Responsive Interface Decision Record

Coordinate one responsive interface through real content and people, layout requirements, bounded CSS/unit scenarios, representative reflow and interaction testing, controlled implementation, and named acceptance.

6 steps13 toolsStart project

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Reference & details

How it works

Color Space Conversion

The Viewport Size Calculator converts between RGB, HSL, HSV, and hex using standard linear transforms. Gamma-correct sRGB values are assumed unless otherwise noted.

HSL ↔ RGB via standard cylindrical transform

Accessibility Checks

Contrast ratios are computed per WCAG 2.1 relative luminance formula. Results indicate AA and AAA compliance for normal and large text.

Contrast = (L1 + 0.05) / (L2 + 0.05)

Output Formatting

Generated values are emitted in copy-ready formats (hex, CSS, Tailwind, SVG). Precision is tuned for design tools without unnecessary floating-point noise.

Updated: July 2026

Example Scenarios

A UI designer uses the Viewport Size Calculator to explore complementary colors and verify WCAG contrast before handing specs to developers.

A front-end developer checks spacing, ratio, or typography values with the Viewport Size Calculator while implementing a Figma mockup in CSS.

A freelancer generates live examples with the Viewport Size Calculator during a client call to agree on visual direction without switching tools.

FAQ

Yes, all processing happens in your browser. No data is sent to any server — your input stays on your device and is never stored or logged.

Yes, it's completely free with no registration required. Use the Viewport Size Calculator as often as you need with no limits, accounts, or subscriptions.

Once loaded, the tool runs entirely in your browser without needing a constant connection. Your data is processed locally for speed and privacy.

The tool works in all modern browsers including Chrome, Firefox, Safari, and Edge. No plugins or extensions are required.

Yes. Use the copy button or select the output text directly. Results are ready to paste into code editors, documents, or other apps.

About Viewport Size Calculator

Use our free Viewport Size Calculator for fast, accurate results in your browser. No signup or installation required — works on any device.