What is the best resolution for my photos, wall art and posters?

Higher resolution photos are clearer and contain more detail.

Digital image resolution is expressed as pixels (or dots) across by pixels down, such as 640 x 480, meaning 640 pixels across by 480 pixels down. The best printable resolution is 300 dots per inch. 

Extremely low resolution will look "blocky" or pixelated. Imagine only 4 dots per inch: you would see four colored squares instead of a picture. When there are many pixels, your mind blends the tiny blocks together to form an image.

The digital camera is the most important factor in determining quality of digital images. The greater the number of pixels (up to 300 per inch), the higher the quality of the digital image. Some low-cost cameras give a set number of pixels and shoot only one resolution. Higher-priced cameras offer a pixel range, which enables you to select the best resolution for the size image you want.

Not all photos require high pixels per inch. For instance, you are likely to stand back from a poster, and your eye will blend the pixels together, so 90 pixels per inch is the minimum recommended resolution for posters. The subject matter can also be important: for instance, if you are printing a picture of a crowd of faces or a group shot, and you want to recognize faces in the crowd, you will need a higher pixel count to ensure that each tiny face has a enough visual information.

Use the following chart as a guide for determining the best resolution for various print sizes.  Note that the 4xD (Digital) size is the same ratio as most digital cameras -- 600 x 800 -- so no cropping is required when printing these photos. The 18x24 and 30x40 also have the same 1.33 ratio and require no cropping for most digital cameras.

Size Borderline:
150 res
Better:
180 res
Good:
200 res
Best:
300 res
Wallets (2"x3") 300 x 450  360 x 540  640 x 480  600 x 900 
3.5 x 5 525 x 750 630 x 900 700 x 1000 1050 x 1500
4 x D (4 x 5.33) 600 x 800 720 x 960 800 x 1066 1200 x 1599
4 x 6 600 x 900 720 x 1000 800 x 1200 1200 x 1800
5 x 7 750 x 1050 900 x 1260 1000 x 1400 1500 x 2100
8 x 10 1200 x 1500 1200 x 1500 1600 x 2000 2400 x 3000





Posters

Borderline:
90 res

Better:
150 res

Good:
180 res

Best:
300 res*

11 x 14
990 x 1260 1650 x 2100 1980 x 2520 3300 x 4200
12 x 18 1080 x 1620 1800 x 2700 2160 x 3240 3600 x 5400
16 x 20 1440 x 1800 2400 x 3000 2880 x 3600 4800 x 6000* 
16 x 24 1440 x 2160 2400 x 3600 2880 x 4320 4000 x 6000*
18 x 24 1620 x 2160 2700 x 3600  3240 x 4320 4500 x 6000*
20 x 20 1800 x 1800 3000 x 3000 3600 x 3600 6000 x 6000*
20 x 24 1800 x 2160 3000 x 3600 3600 x 4320 5000 x 6000*
20 x 30 1800 x 2700  3000 x 4500 3200 x 4800* 4000 x 6000*
24 x 36 2160 x 3240 3200 x 4800*  3200 x 4800*  4000 x 6000*
30 x 40 2700 x 3600 3600 x 4800*  3600 x 4800* 4500 x 6000* 
* The longest side of any uploaded image is a maximum of 6000 dots. When the longest side is 6000, the other side is calculated to have the same number of pixels per inch.