How is maximum print size calculated from megapixels?

The tool first converts megapixels and aspect ratio into pixel dimensions, since width times height equals the total pixels and their ratio is fixed. It then divides each dimension by the target DPI to get inches, so a 6000 by 4000 pixel image at 300 DPI prints 20 by 13.3 inches.

What DPI do I need for a good photo print?

300 DPI is the standard for fine prints viewed up close and is what most labs assume. 240 DPI is excellent for everyday photo prints, while 150 DPI is fine for large prints viewed from a distance. 360 DPI suits critical work inspected closely, such as gallery pieces.

Why does aspect ratio change the pixel dimensions?

Total pixels are fixed by the megapixel count, but how they split between width and height depends on the aspect ratio. A 24-megapixel sensor at 3:2 is about 6000 by 4000 pixels, while the same count at 1:1 is roughly 4900 by 4900, which changes the maximum print proportions.

Can I print larger than the 300 DPI size?

Yes. Large prints are usually viewed from farther away, so they look perfectly sharp at 150 DPI or even less. The 150 DPI row shows how much bigger you can go for wall art and posters, often double the linear size of the 300 DPI figure.

Does upscaling software change these numbers?

Modern AI upscalers can add convincing detail and let you print beyond the native pixel limit, but the figures here reflect the true optical resolution your sensor captured. Use these as the honest baseline, then treat any upscaling as a bonus rather than a guaranteed quality gain.

Megapixel to Print Size Calculator

How big can you print a photo before it starts to look soft? This calculator turns your camera’s megapixel count into the maximum print dimensions at four common print resolutions, so you know exactly where pixel count stops being the limiting factor.

How it works

Megapixels tell you the total number of pixels, and the aspect ratio tells you how they are split between width and height. Solving the two together:

height (px) = √(megapixels × 1,000,000 ÷ ratio), width (px) = height × ratio

where ratio is width ÷ height (for example 1.5 for 3:2). To find the print size, divide each pixel dimension by the target DPI:

inches = pixels ÷ DPI, centimetres = inches × 2.54

A higher DPI packs the same pixels into a smaller, crisper print; a lower DPI spreads them across a larger one.

Worked example

A 24-megapixel camera at 3:2:

height = √(24,000,000 ÷ 1.5) ≈ 4000 px, width ≈ 6000 px
At 300 DPI: 6000 ÷ 300 = 20 in × 13.3 in (50.8 cm × 33.9 cm)
At 150 DPI: 40 in × 26.7 in — a large wall print that still looks sharp from a metre away

Tips and notes

300 DPI is the safe “viewed up close” standard; 150 DPI is fine for posters seen from a distance.
Viewing distance matters as much as DPI: the bigger the print, the farther back people stand.
Cropping reduces effective megapixels, so recalculate with the cropped pixel count for the real limit.
All maths runs locally in your browser; nothing about your images is uploaded.