The Resolution to DPI converter allows you to turn image or screen resolution (width × height in pixels) and diagonal size (in inches) into accurate DPI/PPI. This free online tool helps designers, photographers, and gamers verify pixel density, check monitor sharpness, and prepare print-ready files at 300 DPI or higher.
Resolution to DPI Resolution to PPI
The Calculator — Resolution to DPI / PPI
Use the two tabs to match your goal and search intent:
Resolution to DPI (for print workflows) and Resolution to PPI (for screens/monitors).
Both tabs use the same math and give identical numeric results; we label both to help users looking for
resolution to DPI online or resolution to PPI.
- Resolution to DPI → get dots-per-inch for printing from width × height (pixels) and diagonal (inches).
- Resolution to PPI → get pixels-per-inch for displays from the same inputs (used for monitors, laptops, phones).
Example: 1920×1080 at 24″ → √(1920² + 1080²) ÷ 24 ≈ 92 PPI (same numeric value for DPI in print math).
- Enter whole numbers for width and height (e.g.,
1920,1080). - Enter screen diagonal in inches (e.g.,
27). If you only know centimeters, divide by2.54. - Click Convert to see DPI/PPI instantly.
Tip: For print, typical targets are 300 DPI (magazines, brochures) and 150 DPI (large posters viewed from a distance).
For screens, higher PPI means sharper text and UI.
What is DPI vs PPI?
When people talk about resolution, two terms often appear: DPI and PPI.
Although they are sometimes used interchangeably, they describe different things. Understanding the difference
helps you know how to calculate DPI from resolution correctly and why it matters in both printing and screens.
- DPI (Dots Per Inch) → Measures how many dots of ink a printer can place in one inch of paper.
Higher DPI = sharper, more detailed print quality.
Example: magazines usually require 300 DPI. - PPI (Pixels Per Inch) → Measures pixel density on digital screens (monitors, laptops, smartphones).
Higher PPI = crisper text, sharper images, and better viewing experience.
In practice, many people say “DPI” when they really mean “PPI.” Our Resolution to DPI converter handles both terms:
the formula is the same, so whether you enter resolution for print or for a monitor, the calculator returns the correct numeric value.
Quick takeaway:
DPI = print quality (dots of ink on paper).
PPI = screen sharpness (pixels per inch on display).
Both answer the question: “how does DPI relate to pixels?”—it’s about how many visual units fit into one inch.
How to Calculate DPI from Resolution
To find display density from pixel resolution, use the Pythagorean theorem on pixel dimensions and divide by the physical diagonal.
This answers exactly how to calculate DPI from resolution (aka resolution to DPI):
DPI (or PPI) = √(width² + height²) ÷ diagonal (inches)
Worked Example
Resolution 1920×1080 on a 24″ monitor:
√(1920² + 1080²) = √(3,686,400 + 1,166,400) = √4,852,800 ≈ 2202.9 px
2202.9 ÷ 24 ≈ 91.8 DPI (PPI)
Step-by-Step
- Enter the diagonal size in inches.
- Enter the width in pixels.
- Enter the height in pixels.
- Click Convert to get DPI/PPI.
Quick Reverse (for printing): 300 DPI ↔ pixels
If you need 300 DPI resolution to pixels (or 300 DPI to resolution), use
pixels = inches × DPI.
Examples:
- 4×6 in at 300 DPI → 1200×1800 px
- 8×10 in at 300 DPI → 2400×3000 px
- 2×2 in at 600 DPI (passport quality) → 1200×1200 px (600 DPI to resolution)
To increase resolution of an image to 300 DPI, you either resample (adds pixels, may soften detail)
or keep pixels the same and print smaller so that pixels per inch increase.
Tip: Our calculator returns the same numeric value whether you call it DPI or PPI—perfect for
how to calculate DPI from resolution queries and quick resolution to DPI checks.
Common Conversions & Examples
Here are quick reference values people search for when converting resolution to DPI or using a
DPI to resolution calculator. These presets help you check common screens and print sizes instantly.
Full HD (1920×1080)
| Screen Size | Approx. DPI (PPI) |
|---|---|
| 24″ | ≈ 92 DPI |
| 27″ | ≈ 82 DPI |
| 32″ | ≈ 69 DPI |
4K UHD (3840×2160)
| Screen Size | Approx. DPI (PPI) |
|---|---|
| 27″ | ≈ 163 DPI |
| 32″ | ≈ 138 DPI |
Print Resolutions
For printing, use the rule pixels = inches × DPI. Below are standard conversions at 300 DPI and 600 DPI:
- 300 DPI:
- 4×6 in → 1200×1800 px
- 8×10 in → 2400×3000 px
- 600 DPI:
- 2×2 in logo → 1200×1200 px
These examples answer popular queries like 300 DPI in resolution, 300 DPI resolution to pixels, and 600 DPI to resolution.
Change Image to 300 DPI
Many users search for how to increase resolution of image to 300 DPI or
change DPI and size of image online. Here’s a clear step-by-step guide for both Photoshop and free online converters.
Photoshop Method
- Go to Image → Image Size.
- Uncheck Resample (keeps original pixel count).
- Set Resolution = 300 DPI, then click OK.
- If you need to truly add pixels, check Resample and select a method (e.g., Bicubic, Preserve Details).
Online Tools
- Upload your image to a Resolution to DPI converter online.
- Set the target DPI to 300.
- Enable Resample only if you want more pixels (bigger file size).
Rule of Thumb
For sharp printing: Pixels = Inches × DPI.
Example: a 10 × 8 in photo at 300 DPI → 3000 × 2400 px.
DPI to Resolution (Reverse Calculator)
Sometimes you know the required DPI and the print size in inches, and you need to calculate the pixel dimensions.
Formula: Pixels = Inches × DPI (apply separately for width and height).
This is exactly how a dpi to resolution calculator works.
| Print Size | @300 DPI | @150 DPI |
|---|---|---|
| 4 × 6 in | 1200 × 1800 px | 600 × 900 px |
| 8 × 10 in | 2400 × 3000 px | 1200 × 1500 px |
Use Cases — How Does DPI Relate to Pixels?
Understanding how DPI relates to pixels is crucial in different fields.
Whether you’re printing, designing, or comparing screens, DPI defines how many pixels fit into an inch, and therefore, how sharp the result looks.
- Printing: Magazines, brochures, and posters use 300 DPI as the gold standard for sharp results.
Large posters viewed from a distance can often use 150 DPI without noticeable quality loss. - Design: In Photoshop or Illustrator, match your pixel dimensions to the final print size × desired DPI.
Example: 8×10 in at 300 DPI → 2400×3000 px canvas. - Monitors: Screen sharpness depends on PPI. Two displays with the same resolution can look very different if their physical sizes vary.
A 24″ 1080p screen ≈ 92 PPI vs. a 32″ 1080p screen ≈ 69 PPI.
Resolution to DPI — FAQ
Quick answers to the most common resolution to DPI questions.
How to calculate DPI from resolution?
Use the formula: DPI = √(width² + height²) ÷ diagonal (inches). (See the calculator section.)
What is “300 resolution” in DPI?
It usually means 300 DPI, the professional print standard.
How much DPI for 1920×1080?
~92 DPI at 24″; ~82 DPI at 27″; ~69 DPI at 32″.
How to change image resolution to 300 DPI?
In Photoshop: Image → Image Size → set Resolution = 300.
Check Resample only if you need more pixels.
What is 600×600 pixels at 300 DPI?
600 ÷ 300 = 2 inches per side → 2×2 in print size.
How many pixels is 600 DPI?
DPI is not pixels alone. Formula: pixels = inches × DPI.
Can I change 72 PPI to 1040 DPI?
Only by resampling (generating new pixels). Metadata alone won’t add detail.
Related Tools
Explore more free calculators to convert DPI, PPI, pixels, and inches for print, design, and screen work.
For more details, see the
DPI article on Wikipedia.