Before you send a file to print this week

How big can you print it?

Print size equals pixels divided by DPI: enter your image's pixel width and height plus a target DPI, and the calculator on the right shows the largest sharp print size instantly, no upload required.

300 DPI

Print Size Calculator

Largest sharp print20.0 × 13.3 in

At 300 DPI, a 6000×4000px image prints sharp up to 20.0 × 13.3 in (50.8 × 33.8 cm).

Open full calculator →
Formula: pixels ÷ DPI 300 DPI photo-print convention Nothing you type leaves the tab
Exact DPI math No account, no upload, no catch Works from a phone at the print counter Free, same as every calculator here
01 / Which calculator you need

Print Size & DPI Calculators

Three calculators, one job: tell you whether your file is ready for the print you want.

Guess the DPI wrong and the print shop hands back something soft and pixelated. Do the math first.

A walk through the formula

What the print size calculator is actually doing

Take the numbers already loaded in the calculator at the top of this page: a 6000×4000px file, 300 DPI. The script behind it does one division, twice: 6000 ÷ 300 = 20 inches, and 4000 ÷ 300 = 13.3 inches. That is the entire calculation. No hidden correction factor, no rounding trick, nothing that depends on the file format or the camera that shot it. Pixels in, DPI chosen, inches out.

Change the DPI and watch what happens to the same file. Drop to 150 DPI and that 6000×4000px image jumps to 40 × 26.7 inches, twice as large in each direction, because you have cut the divisor in half. Push up to 600 DPI for an archival print and the same file shrinks to 10 × 6.7 inches. The pixel count never changes. Only the DPI you are asking those pixels to satisfy does. This is why two people can argue about "how big can I print this" and both be right: they are answering the question at different DPI.

The Required Resolution Calculator runs the same formula backward. Tell it you want a 20 × 30 in print at 300 DPI and it multiplies: 20 × 300 = 6,000px, 30 × 300 = 9,000px, for a file that needs roughly 54 megapixels. Most phone cameras and a fair number of older DSLRs do not clear that bar, which is worth knowing before you order the print, not after it arrives soft.

Common costly mistakes with DPI math

The mistake that costs people the most money is trusting a file's reported DPI instead of its pixel count. A JPEG can say "72 DPI" in its metadata and still contain 6000×4000 pixels, plenty for a large, sharp print. That metadata number is a leftover from screen-display defaults, not a ceiling. If you resize a print based on the label in the file properties instead of the actual pixel dimensions, you will either undersell an image that could print much bigger, or worse, overestimate a small one.

The second mistake is measuring the wrong print size. Framed prints usually specify the visible image, not the mat or frame opening around it, and printers occasionally quote the paper size, which runs slightly larger than the trimmed image. A half-inch difference does not sound like much until it turns a 300 DPI print into a 280 DPI print at the edges, or bumps a file that just barely met spec into one that does not.

The third is upscaling and calling it resolution. Software can add pixels between existing ones, and that can carry a file over the required-resolution line on paper. It cannot manufacture detail that was never captured. A heavily upscaled 12MP file printed at 24 × 36 in will hit the pixel-count target and still look softer than a native 54MP capture at the same size, because the calculator only checks pixel count, not whether those pixels are real.

The fourth, smaller but common: forgetting that cropping removes pixels permanently. Crop a 6000×4000px photo down to a tight square and you are no longer working with 24MP, you are working with whatever survived the crop. Run the crop through the DPI Calculator before ordering the print, not after.

How to read the result

Each calculator on this site returns the same three numbers in different combinations: a pixel count, a print size in inches, and a DPI. Whichever two you already have, the third is what the tool solves for. The result box tells you the ceiling, not a recommendation. A print size result of "20.0 × 13.3 in" at 300 DPI means that is the largest size this file supports at that sharpness standard. Printing smaller is always fine. Printing larger means either the DPI drops below 300, or a lab has to upscale the file to compensate.

The DPI Calculator's quality rating (Excellent, Good, Acceptable, Low) is reading the lower of your width DPI and height DPI, since a mismatched aspect ratio between the image and the frame size will always be limited by whichever dimension is tightest. If width comes back at 340 DPI but height comes back at 210, the print quality is 210 DPI, not the average of the two.

None of the three tools ask what the print is for, and that omission is deliberate. Portraits, photo books and anything framed close by call for the higher end of the DPI scale. A banner or trade-show graphic seen from six feet away can run at a much lower setting and still look sharp, because distance does the resolving that extra pixels would otherwise do. Pick the tier that matches how the print will actually be viewed, then let the calculator handle the arithmetic.

02 / Reference data

Print Resolution Reference (2026)

Every common print size mapped to the pixel dimensions it needs at 150, 300 and 600 DPI, computed straight from the pixels ÷ DPI formula above.

Good to know

Print DPI FAQs without the fluff

Why does my file say 72 DPI but still print sharp at a large size?

Because that number is metadata left over from screen-display defaults, not a measurement of the file's real capability. What matters is pixel count. Run the actual width and height through the Print Size Calculator and ignore whatever DPI the file properties claim.

Should I measure the framed size or the image size?

The image size, meaning the visible print itself, not the mat or the frame opening. Printers occasionally quote paper size too, which runs a little larger than the trimmed image. Use the smaller, exact number.

Does upscaling actually increase my usable resolution?

It increases the pixel count a calculator will accept, but not the real detail in the image. A heavily upscaled file can clear the required-resolution bar on paper and still look softer in person than a native capture at the same size.

Does cropping change what these calculators tell me?

Yes. A crop permanently removes pixels, so the file's maximum sharp print size shrinks along with it. Check the cropped dimensions, not the original camera export, before ordering a print.