Developer Tools
Viewport Size Calculator
Calculate viewport units (vw, vh) and convert between pixels and viewport percentages. Plan responsive designs with viewport-relative sizing.
Use Viewport Size Calculator to get instant results without uploads or sign-ups. Everything runs securely in your browser for fast, reliable output.
Your results will appear here.
About this tool
Viewport units (vw, vh, vmin, vmax) are relative to browser window size. Our Viewport Calculator converts pixels to viewport units for truly responsive designs.
Use viewport units for hero sections, full-screen layouts, and fluid typography. 1vw = 1% of viewport width, 1vh = 1% of viewport height.
Usage examples
Full Width
Element spans viewport width
width: 100vw; (full viewport width)
Fluid Typography
Font size scales with viewport
font-size: 4vw; (4% of viewport width)
How to use
- Enter "Viewport Width" (typically 1920px for desktop).
- Enter "Pixel Value" to convert.
- Click "Calculate" to get vw/vh equivalents.
- Use for responsive font sizes and spacing.
Benefits
- Convert px to vw/vh
- Responsive units
- Fluid layouts
- Scalable typography
- Full-screen elements
- Modern CSS units
FAQs
What are viewport units?
Viewport units: vw (1% of viewport width), vh (1% of viewport height), vmin (1% of smaller dimension), vmax (1% of larger dimension). Example: 50vw = 50% of screen width. On 1920px wide screen, 10vw = 192px. Responsive without media queries!
When should I use vw/vh instead of pixels?
Use viewport units for: full-screen sections (100vh hero), fluid typography (clamp(16px, 2vw, 24px)), responsive spacing, elements that scale with screen. Use pixels for: fixed UI elements, icons, borders, small details. Mix both for flexibility.
What is the 100vh mobile browser problem?
On mobile, 100vh includes address bar height, causing content to be cut off when address bar appears. Solution: use min-height: 100vh; with scrolling, or CSS.supports(100dvh) with dynamic viewport units (dvh, svh, lvh - Chrome 108+), or JavaScript to calculate actual height.
How do I calculate vw from pixels?
Formula: vw = (pixels / viewport width) × 100. Example: 192px on 1920px viewport = (192 / 1920) × 100 = 10vw. Reverse: pixels = (vw / 100) × viewport width. On 1920px screen, 5vw = (5 / 100) × 1920 = 96px.
What is fluid typography with clamp()?
clamp() creates responsive text: clamp(min, preferred, max). Example: font-size: clamp(16px, 2vw, 24px); Text is 2vw but never below 16px or above 24px. Scales smoothly between breakpoints without media queries. Modern CSS technique for accessibility.
Can I use calc() with viewport units?
Yes! Combine viewport units with calc(): width: calc(100vw - 40px); (full width minus 40px padding), height: calc(100vh - 60px); (full height minus header), font-size: calc(14px + 1vw); (base 14px + scale). Very powerful for hybrid layouts.
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