How to convert pixels to inches?

Why Unit Conversion Matters

When working with digital graphics, web design, or document rendering, developers often need to convert between various units of measurement, such as pixels (px), centimeters (cm), inches (in), or points (pt). In .NET applications, this task becomes simple and accurate with Aspose.HTML for .NET, a powerful library that provides full control over document rendering and geometric calculations. When rendering HTML, MHTML, EPUB, or SVG documents, precise physical dimensions ensure accurate print layout, consistent display across devices, and high-quality responsive exports to formats like PDF or PNG.

This article explains how to convert pixels to inches in C# using the Aspose.Html.Drawing namespace – with clean, readable code and a clear explanation of how unit conversion works. It provides a reliable Unit class that handles all common unit types and automatically applies conversion formulas according to the CSS standard.

Convert Pixels to Inches

Here’s a simple example demonstrating how to convert 800 pixels into inches using Aspose.HTML for .NET.

 1// Convert pixels to inches using C#
 2
 3// Define the number of pixels to convert
 4var px = Unit.FromPixels(800);
 5
 6// Convert pixels to inches
 7var inch = px.GetValue(UnitType.In);
 8
 9// Print the converted value with two decimal places
10Console.WriteLine(inch.ToString("F2"));

Example-ConvertPxToIn.cs hosted with ❤ by GitHub

Import the Aspose.Html.Drawing Namespace. The Aspose.Html.Drawing namespace contains the Unit class and the UnitType enumeration.
Use the FromPixels() method to define a unit representing 800 pixels.
The GetValue() method converts the pixel value to the specified unit type. You can convert pixels not only to inches but also to other units of length defined in the UnitType fields.
The final line prints the calculated value in inches.

Technical Details

Aspose.HTML uses the CSS absolute length unit conversion model – standard DPI-based conversion formulas:

1 inch = 96 pixels
1 inch = 2.54 centimeters

Therefore:

1cm = (pixels / 96) * 2.54

For example:

11000 px ≈ 26.46 cm

This makes conversions between display units (px) and physical units (cm, in, mm) completely accurate and consistent across platforms.

Note: Aspose.HTML for .NET uses a PPI value of 96 as the basis for pixel conversions. This means that approximately 96 pixels are equivalent to one inch. If you want to use a different PPI value for your conversions, please use the free online Pixel Calculator.

FAQ

1. Can I convert pixels to other units like millimeters or centimeters?

Yes. Simply change the target unit in GetValue():

1var mm = px.GetValue(UnitType.Mm);
2var cm = px.GetValue(UnitType.Cm);

2. Does the conversion depend on screen DPI?

No, Aspose.HTML uses the CSS standard DPI (96) to ensure consistent and device-independent results.

3. Is it possible to convert from inches back to pixels?

Absolutely:

1var inch = Unit.FromInches(10);
2var px = inch.GetValue(UnitType.Px);

4. What is the difference between DPI and PPI?

DPI (Dots Per Inch) is the number of ink dots a printer can place in one inch and is typically used in the context of printing. PPI (Pixels Per Inch) is the number of pixels in a digital image or on a screen. In web context and CSS, DPI is typically used for conversion, which corresponds to the CSS standard of 96 DPI.

So:

For print – DPI
For screens – PPI
In documentation and code – DPI (CSS standard: 96 DPI)