dp sp pt px Converter

How Does the dp sp pt px Converter Work?

The dp sp pt px Converter is a free online tool designed for mobile developers who need to translate between density-independent units used by Android, iOS, and web platforms. Mobile screens come in a wide range of physical sizes and pixel densities. Without a density-independent unit system, a 16-pixel icon would appear large on a low-density screen and tiny on a high-density screen. Android solves this with dp (density-independent pixels) and sp (scale-independent pixels for text), while iOS uses pt (points). This converter lets you enter a value in any of these units and instantly see the equivalent pixel values across every standard screen density.

Understanding Screen Density Units

Android defines a baseline density of 160 dpi, called mdpi. At mdpi, 1 dp equals exactly 1 physical pixel. As screen density increases, more physical pixels are packed into the same area. At hdpi (240 dpi), the multiplier is 1.5x, so 1 dp becomes 1.5 pixels. At xhdpi (320 dpi) it is 2x, at xxhdpi (480 dpi) it is 3x, and at xxxhdpi (640 dpi) it is 4x. This means a 24dp icon requires a 24px asset for mdpi, a 36px asset for hdpi, a 48px asset for xhdpi, a 72px asset for xxhdpi, and a 96px asset for xxxhdpi.

Android Resource Directories

Android uses density-specific resource folders to serve the correct asset size to each device. When you place image assets in drawable-mdpi, drawable-hdpi, drawable-xhdpi, drawable-xxhdpi, and drawable-xxxhdpi, the system automatically selects the right folder based on the device screen density. This converter shows you exactly which pixel dimensions your assets need for each folder.

iOS Points and Scale Factors

iOS uses a similar concept called points. Non-Retina devices display at 1x (1 point = 1 pixel), Retina devices at 2x, and Super Retina devices at 3x. When preparing image assets for iOS, you provide @1x, @2x, and @3x versions. A 24pt icon needs a 24px @1x image, a 48px @2x image, and a 72px @3x image. The point system in iOS is functionally equivalent to Android dp — both represent a density-independent measurement that maps to different pixel counts on different hardware.

Common Reference Sizes

Android Material Design defines several standard sizes that developers frequently convert: the app toolbar height is 56dp, standard icons are 24dp, the floating action button (FAB) is 56dp, and the minimum touch target is 48dp. Knowing the pixel equivalents of these sizes across densities helps when creating custom assets, debugging layout issues, or communicating specifications with designers.