Convert ISO C0-C10 paper sizes to pixel dimensions based on DPI/PPI for screen or print. Ideal for designers and print professionals.

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Accurately calculate the physical dimensions between pixels and millimeters based on PPI density. Ideal for UI design and print typography.

Pixel to Centimeter Converter
Accurately convert pixel lengths to physical centimeter dimensions based on PPI (Pixels Per Inch). Ideal for UI design, print layouts, and screen adaptation.

PX to PT Converter
A pixel (PX) to point (PT) unit conversion tool for designers and developers. Supports custom PPI for typography and layout adaptation.

Online JWT Parser & Decoder
Parse JWT headers, payloads, and key information online. No installation required—just paste and decode.

PX to REM Converter
A bidirectional PX to REM converter for front-end developers and designers, featuring customizable root font sizes.
When designing print drafts or digital content, how do you ensure that ISO C-series paper sizes (like C4 envelopes) accurately convert to the correct pixel dimensions at different DPI/PPI resolutions? This tool is specifically designed to solve this problem. It automatically calculates the corresponding pixel width and height based on the physical dimensions (in millimeters) of C-series paper and your specified dots per inch (DPI/PPI) resolution. C-series paper is a size system defined in the ISO 216 standard, primarily used for envelopes. It has an aspect ratio of 1:√2, with sizes falling between the A and B series. For example, a standard C4 paper (229mm × 324mm) at 300 DPI will output an image size of approximately 2705px × 3827px.
Q: How many pixels is a C4 paper at 300 DPI?
A: It is approximately 2705px wide and 3827px high. This is an approximate integer value obtained by converting the physical dimensions of C4 paper (229mm × 324mm) to inches and multiplying by 300.
Q: What is the difference between DPI and PPI in this tool? Are the conversion results applicable to all scenarios?
A: In this tool, both DPI (dots per inch for print) and PPI (pixels per inch for screens) are treated as "pixels/dots per inch" parameters, and the calculation logic is identical. However, please note that the resulting pixel dimensions only represent the theoretical size of the image at the set resolution. Actual print or display results are also affected by device calibration, software rendering, and image interpolation algorithms. We recommend using these results as a baseline reference.
Before using, please note: 1. The DPI/PPI value you enter directly affects the accuracy of the results; please set it according to your final output medium (screen/printer). 2. Results are whole pixels rounded from the calculated values, so there may be a minor variance of ±1 pixel. 3. The tool does not process image files; it only provides dimension conversions. All calculations are performed locally in your browser with no data uploads, ensuring your privacy and security.
To ensure consistency between your design draft and the final printed product, we recommend following the "physical size first" principle: first, determine the paper size of the final product (e.g., C4), and then set the DPI/PPI based on the printer's requirements or screen standards. A typical use case: To create a digital draft for a print piece that needs to fit into a C4 envelope, with a known print requirement of 300 DPI. Using this tool, select "C4" and enter "300" to get a canvas size of 2705 × 3827 pixels. Creating a new document with these dimensions in software like Photoshop will maximize the accuracy of the physical dimensions after printing.