How do I convert px to vw manually?

Divide the pixel value by your target viewport width, then multiply by 100. For example, 320px on a 1920px desktop is (320/1920) × 100 ≈ 16.67vw. For mobile-first (375px viewport), the same 320px becomes ≈ 85.33vw.

What is the 100vh mobile address-bar bug?

On mobile browsers, the address bar shows/hides as you scroll. When it hides, the viewport grows — and 100vh elements jump in size. Modern CSS introduced dvh (dynamic viewport height) and svh / lvh (small/large) to handle this. Use 100dvh on mobile to avoid the jump.

Should I use vw for typography?

Not alone — pure vw font-size becomes tiny on phones and huge on 4K monitors. Use clamp() to set min/max bounds: font-size: clamp(1rem, 2vw, 1.5rem) gives a rem floor, vw-scaled middle, and rem ceiling for fluid, bounded typography.

px to vw Converter — Free Online Viewport Unit Calculator

Home/Design Tools/px ↔ vw / vh Converter

Visual Layout Preview

320px

Generated CSS

width: 16.6667vw; /* 320px */

What Are vw and vh Units?

vw (viewport width) and vh (viewport height) are relative CSS units calculated against the browser window. 1vw = 1% of the viewport width; 1vh = 1% of the viewport height. Unlike % (relative to parent) or rem (relative to root font-size), viewport units are always relative to the browser window — making them perfect for hero sections, full-bleed images, fluid typography, and responsive layouts that need to scale with screen size regardless of container nesting.

px to vw / vh Converter Online — What This Tool Does

This free px to vw converter performs bidirectional conversion in your browser. Enter a pixel value and your target viewport width (or height) to see the vw / vh equivalent, with a live visual preview showing the computed pixel size.

How to Convert px to vw

Enter a pixel value in the px field.
Set the Viewport Width to your target screen width (default 1920px for desktop). For mobile-first design, try 375px (iPhone) or 412px (typical Android).
Toggle VW / VH to switch between width-based and height-based conversion.
The vw equivalent appears instantly: px / viewport × 100.
The visual preview shows the computed pixel width.

vw vs % — Key Differences

vw — always relative to viewport (browser window). Survives nesting.
% — relative to immediate parent. Changes meaning at every nesting level.
Use vw for hero sizing, full-bleed elements, and fluid typography that should scale with screen size.
Use % for components that should fill their container regardless of viewport.

Mobile Viewport Caveats

vh changes on mobile — when the address bar shrinks during scrolling, the viewport grows, and 100vh elements jump. Use 100dvh (dynamic viewport height) on modern browsers to avoid this.
svh / lvh / dvh — small/large/dynamic viewport units (CSS Values Level 4) give more precise control on mobile. 100svh = smallest viewport height (with browser chrome visible).
Test in landscape — vw / vh values that look right in portrait can break dramatically in landscape orientation.
Don't use vw for typography alone — use clamp() to set min/max bounds: font-size: clamp(1rem, 2vw, 1.5rem) avoids tiny text on phones and huge text on 4K monitors.

Tips & Tricks

Fluid typography with clamp() — combines rem floor + vw scaling + rem ceiling for typography that adapts cleanly across all screen sizes.
Pair vw with max-width — width: 90vw; max-width: 1200px for centred, capped containers.
Use 100dvh for full-height sections on mobile — avoids the jumpy address-bar bug.
For container queries — when you need sizing relative to a parent's actual rendered width (not viewport), use CSS container queries with cqw / cqh instead of vw / vh.

Related Tools

px ↔ rem Converter — typography and design-system sizing.
px ↔ em Converter — component-scoped sizing.
px ↔ % Converter — fluid layout sizing relative to parent.
rem ↔ em Converter — translate between the two relative font units.
Color Picker — pick brand colours for your design system.

Is My Data Sent to a Server?

No. All unit conversion runs entirely in your browser using simple JavaScript math. The values you enter — including any proprietary design-system tokens — never leave your device. There is no upload, no logging, and no analytics on the numbers you enter.