About DPI Calculator
Calculate printing Dots Per Inch (DPI) requirements for commercial offset presses based on halftone line screens (LPI) to avoid moiré artifacts.
Key Capabilities & Features
- Halftone line screen rule calculation: image input DPI = 2 × LPI
- Presets for newsprint (85 LPI), book paper (133 LPI), glossy magazine (150 LPI), and fine art (200 LPI)
- Pre-press resolution guide preventing moiré pattern artifacts
- Direct technical explanation of commercial CMYK dot generation
How to Use DPI Calculator
Select Line Screen (LPI)
Choose your commercial printing press specification.
Inspect Required DPI
Review the pre-press file resolution required for clean rasterization.
Prepare Press Files
Export your artwork at the calculated DPI benchmark.
Privacy & In-Browser Execution Guarantee
100% client-side calculation. Your prepress data stays private in your browser.
Frequently Asked Questions
What is the difference between DPI and LPI?
DPI (Dots Per Inch) refers to digital printer or image dots, while LPI (Lines Per Inch) measures the mechanical halftone frequency of commercial offset printing plates.
Why does 150 LPI require a 300 DPI file?
The Nyquist-Shannon sampling theorem and pre-press raster image processors (RIP) require a quality factor of 2.0x (2 pixels per halftone line) to accurately render tonal gradients.