Image Resolution Calculator
Enter any pixel resolution and see what it amounts to: total megapixels, the simplified aspect ratio, whether it matches a named standard like 1080p, QHD, 4K or 8K, and how large it prints at 300 DPI. Megapixels are simply width times height divided by a million, so 3840 × 2160 (4K) is about 8.3 megapixels. The calculator ties resolution together with the ratio and print size so you can size an image for a screen or a print at a glance.
How to use this tool
- Enter the image width and height in pixels.
- Optionally set a print DPI for the print-size estimate.
- Read the megapixels, aspect ratio and any matching standard format.
- Check the print size to see how large the image prints sharply.
- Compare against HD, QHD, 4K and 8K using the named standards in the result.
The formula
A resolution describes a pixel grid. Multiplying its dimensions gives the total pixel count, usually quoted in megapixels; reducing them gives the aspect ratio; and dividing by a print density gives the physical size it can be printed at.
total_pixels = width × height
megapixels = total_pixels ÷ 1,000,000
print_inches = pixels ÷ DPI- megapixel
- One million pixels
- width × height
- Always quoted horizontal first
Doubling a resolution quadruples the pixel count, because both dimensions double. 4K has four times the pixels of 1080p, not twice — which is also why it needs roughly four times the bitrate.
Worked examples
4K UHD
- Given
- 3840 × 2160
- Result
- ≈ 8.3 MP, 16:9
3840 × 2160 = 8,294,400 pixels ÷ 1,000,000 ≈ 8.29 megapixels, at a 16:9 ratio — matching the 4K UHD standard.
Full HD
- Given
- 1920 × 1080
- Result
- ≈ 2.1 MP, 16:9
1920 × 1080 = 2,073,600 pixels ≈ 2.07 megapixels, the 1080p standard.
Print size
- Given
- 6000 × 4000 at 300 DPI
- Result
- 20 × 13.33 in
6000 ÷ 300 = 20 inches wide and 4000 ÷ 300 ≈ 13.33 inches tall — a 24-megapixel camera file prints large and sharp.
Frequently asked questions
Multiply the width and height in pixels and divide by one million. A 3840 × 2160 image is 8,294,400 pixels, or about 8.3 megapixels. Megapixels measure how many pixels an image contains, which sets the maximum detail and print size — but not, on its own, the image quality.
1080p (Full HD) is 1920 × 1080. 4K UHD is 3840 × 2160 — four times the pixels, hence “4K”. True DCI 4K used in cinema is slightly wider at 4096 × 2160. QHD (1440p) sits between them at 2560 × 1440. This calculator names whichever standard your dimensions match.
Not necessarily. Megapixels set the pixel count, but quality also depends on the sensor, lens, lighting, focus and compression. A well-shot 12-megapixel photo can look better than a poor 48-megapixel one. Megapixels mainly determine how large you can display or print before pixels become visible.
Divide each pixel dimension by your target DPI. At 300 DPI, a 6000 × 4000 image prints 20 × 13.3 inches sharply. Print larger and the effective DPI falls, softening fine detail. This tool shows the print size at your chosen DPI; the print resolution calculator explores DPI trade-offs in more depth.
The calculator simplifies your width and height to their lowest ratio — for example 3840 × 2160 reduces to 16:9. If the dimensions do not reduce to a common ratio exactly, it shows the nearest standard ratio alongside the exact figure so you know how close it is.
Related tools
Simplify any ratio, scale dimensions while keeping proportions, and match common formats.
Print Resolution CalculatorWork out the pixel dimensions, print size or DPI you need for sharp printed output.
Screen PPI CalculatorCalculate a display’s pixel density, dot pitch and quality class from its resolution and size.