Print Size Calculator

1. Enter the megapixels of your camera or image.
2. Choose the aspect ratio the image uses.
3. Set the print resolution in DPI, or leave it at 300.
4. Read the maximum print size in inches and centimeters.

Here is what each result means:

Megapixels tell you how many pixels an image has. Print size depends on how tightly you pack those pixels onto paper, measured in dots per inch, or DPI.

Spread the pixels thinly, at a low DPI, and you get a big but softer print. Pack them densely, at a high DPI, and you get a smaller but sharper print. The megapixel count sets the ceiling on how large you can go at any given sharpness.

First the calculator turns megapixels and the aspect ratio into pixel width and height. Then it divides each by the print resolution to get inches.

1. Find the pixel dimensions from the megapixels and aspect ratio.
2. Divide the width in pixels by the DPI for the print width.
3. Divide the height in pixels by the DPI for the print height.

Multiplying inches by 2.54 gives centimeters. A higher DPI produces a smaller, crisper print from the same pixels.

Take a 24 megapixel photo in the common 3:2 shape, printed at 300 DPI.

Calculation: 24 megapixels in 3:2 works out to 6000 by 4000 pixels. Dividing each by 300 DPI gives 20 by 13.3 inches, or about 50.8 by 33.9 centimeters. Drop the resolution to 150 DPI and the same photo prints twice as large, at 40 by 26.7 inches, though a little softer.

This shows the megapixels needed to print common sizes at a sharp 300 DPI.

300 DPI for Photos

Standard for prints held at reading distance, like photo books and framed 8 by 10s. It gives crisp, detailed results.

150 to 200 DPI for Larger Prints

Posters and wall art viewed from a step or two back look fine at this range, letting you print bigger from the same file.

Under 100 DPI for Banners

Large banners and billboards are seen from far away, so they can use very low DPI without looking soft up close.

Before Ordering Prints

Check the largest size your photo can print sharply, so you avoid ordering a blurry enlargement.

Buying a Camera

See whether a camera's megapixels are enough for the print sizes you care about.

Planning Wall Art

Work out the DPI needed to fill a frame or canvas at the size you want.

1. Ignoring the Aspect Ratio

Megapixels alone do not set the dimensions. A 24 megapixel image is a different size in 3:2 than in 1:1, so the ratio matters.

2. Expecting 300 DPI for Every Size

Very large prints may not reach 300 DPI from a small file. Lowering the DPI is normal for big prints viewed from a distance.

3. Enlarging Beyond the Pixels

Upsizing a small image to a big print does not add real detail. The calculator shows the honest maximum before quality drops.

4. Forgetting Cropping

Cropping removes pixels and lowers the effective megapixels, so the largest sharp print shrinks too.

The math is exact. Pixel dimensions are derived from the megapixels and ratio, so they may differ slightly from a specific camera's exact resolution.

Turn the megapixels and aspect ratio into pixel dimensions, then divide each by the print resolution. A 24 megapixel 3:2 photo is 6000 by 4000 pixels, which at 300 DPI prints 20 by 13.3 inches.

About 7.2 megapixels for a sharp 8 by 10 at 300 DPI, which is 2400 by 3000 pixels. Most modern cameras and phones easily exceed this.

Use 300 DPI for photos held at reading distance. Larger prints viewed from farther away look fine at 150 to 200 DPI, and big banners can use even less.

Yes. Lowering the DPI spreads the same pixels over more inches, so the print gets larger. It also gets softer, which is fine for prints viewed from a distance.

Megapixels only give the total pixel count. The aspect ratio decides how those pixels split into width and height, which sets the actual print dimensions.

More megapixels raise the maximum sharp print size, yes. But lens quality, focus, and noise also affect how good a large print looks, not just the pixel count.

You can, but it does not add real detail. Software can upscale an image, yet the extra pixels are guessed, so very large enlargements from small files look soft.

No. The calculation runs in your browser and nothing you enter is stored or sent anywhere, unless you choose Save, which keeps the result only on this device.

• Dots per inch and print resolution (general reference).
• Image resolution (general reference).