Home Theater & Entertainment TV & Displays 40 40 people found this article helpful How Many Pixels in an Inch (PPI)? There's no one right answer to this question by Tim Fisher General Manager, VP, Lifewire.com Tim Fisher has 30+ years' professional technology support experience. He writes troubleshooting content and is the General Manager of Lifewire. our editorial process Facebook Twitter LinkedIn Tim Fisher Updated on May 05, 2020 TV & Displays Samsung Projectors Antennas HDMI & Connections Remote Controls Tweet Share Email The pixels per inch of a display is what's referred to as the pixel density or PPI. It's a measure of how many pixels you would count if you counted the pixels, horizontal or vertical, that exist in a single inch on your display. There Is No One Answer to Pixels per Inch Lifewire / Kelly Miller If all pixels were the same size, the pixels in an inch would be a known number like how many centimeters in an inch (2.54) or how many inches in a foot (12). However, pixels are different sizes on different displays, so the answer is 58.74 pixels per inch on a 75-inch 4K television, for example, but 440.58 pixels per inch on a 5"-inch full HD smartphone screen. In other words, how many pixels per inch depends on the size and resolution of the screen you're talking about, so we'll have to do some math to get the number you're after for yours. How to Calculate the Pixels in an Inch Before we get into what looks like advanced math (it's not, don't worry), we've done the hard work for you for a number of displays in the Pixels Per Inch Table at the bottom of the page. If you find your display's PPI, move on to How to Use Your Pixels per Inch Number, but if not, we'll figure it out right here with a few simple mathematical steps. What you'll need in any case is the diagonal display size in inches as well as the resolution of the screen. Both of these numbers can be found on the technical specifications page of your display or device. See our page on how to find manufacturer tech support information if you need help digging this up. Here's the full equation for you math savvy folks, but skip right past it for the step-by-step directions: ppi = (√(w²+h²))/d ...where ppi is pixels per inch you're trying to find, w is the width resolution in pixels, h is the height resolution in pixels, and d is the diagonal size of the screen in inches. If you slept during the order of operations chapter in math class, here's how you do this with an example of a 60" 4K (3840x2160) screen: Square the width pixels: 3840² = 14,745,600Square the height pixels: 2160² = 4,665,600Add those numbers together: 14,745,600 + 4,665,600 = 19,411,200Take the square root of that number: √(19,411,200) = 4,405.814Divide that number by the diagonal screen measurement: 4,405,814 / 60 = 73.43 In five short steps, we figured the pixels in an inch on a 60" 4K television to be 73.43 PPI. All you need to do now is repeat those five steps with your display, using your screen's resolution and size. So now you know your display's PPI... but what good is it? If you were just curious, you're done! However, as we alluded to in the introduction above, most of the time a device or display PPI is the first of two steps to getting to something much more practical. Determine How Big an Image Will Look on Another Device Now that you know your screen or device PPI, it's time to put it to good use. You may create or edit an image on your 17-inch laptop with an HD screen (129.584 PPI) but know that you'll be displaying it on an 84-inch 4K UHD display (52.45 PPI) in the office next week. How can you be sure the image is being created large enough or has the right detail? To answer this question, you'll first need to know the PPI of the device or display that you're curious about. We learned how to do that in the last section, or you found one or both numbers in the table below. You'll also need to know the horizontal and vertical pixel dimensions of your image. You're creating or editing that so it should be easy enough to find in your graphics program. Like before, here are the full equations if you're so inclined, but the instructions are below: hsize = w/ppivsize = h/ppi ...where hsize and vsize are the image's horizontal and vertical sizes in inches, respectively, on the other display, w is the width of the image in pixels, h is the height of the image in pixels, and ppi is the PPI of the other display. Here's how you do this if your image is 950x375 pixels in size and the display you're planning for is an 84-inch 4K (3840x2160) screen (52.45 PPI): Divide the width by the PPI: 950 / 52.45 = 18.11 inchesDivide the height by the PPI: 375 / 52.45 = 7.15 inches Here we showed that, no matter how "big" or "small" the image might appear to be on your screen, with pixel dimensions of 950x375, that image will appear to be 18.11" by 7.15" on that 84-inch 4K TV it'll be shown on. Now you can use that knowledge as you see fit — maybe that's just what you were after, or maybe that's not big enough considering that an 84-inch screen is roughly 73 inches across and 41 inches tall! Determine the Size an Image Will Print at Full Resolution You don't need to figure your device or display PPI to figure out how big an image you print will be on paper. All you need to know is information that's contained in the image itself - the horizontal pixel dimension, the vertical pixel dimension, and the image's PPI. All three pieces of data are available in the image's properties which you can find in your graphics editing program. Here are the equations: hsize = w/ppivsize = h/ppi ...where hsize and vsize are the image's horizontal and vertical sizes in inches, respectively, as they'll be printed, w is the width of the image in pixels, h is the height of the image in pixels, and ppi is the PPI of the image itself. Here's how you do this if your image is 375x148 pixels in size and has a PPI of 72: Divide the width by the PPI: 375 / 72 = 5.21 inchesDivide the height by the PPI: 148 / 72 = 2.06 inches Assuming you don't scale the image during the printing process, the image will be physically printed at the size of 5.21 inches by 2.06 inches. Do the math with an image you have and then print it out — it works every time! The DPI resolution your printer is set at, be it 300, 600, 1200, etc., does not impact the size that the image is printed at! This number is very similar to PPI and represents the "quality" by which the image sent to the printer is printed with but should not be included as part of your image size calculations. Pixels Per Inch Tables As promised above, here's our PPI "cheat sheet" which should save you the multi-step math we demonstrated above. PPI Cheat Sheet Size (in) 8K UHD (7680x4320) 4K UHD (3840x2160) Full HD (1920x1080) 145 60.770 30.385 15.192 110 80.106 40.053 20.026 85 103.666 51.833 25.917 84 104.900 52.450 26.225 80 110.145 55.073 27.536 75 117.488 58.744 29.372 70 125.880 62.940 31.470 65 135.564 67.782 33.891 64.5 136.614 68.307 34.154 60 146.860 73.430 36.715 58 151.925 75.962 37.981 56.2 156.791 78.395 39.198 55 160.211 80.106 40.053 50 176.233 88.116 44.058 46 191.557 95.779 47.889 43 204.922 102.461 51.230 42 209.801 104.900 52.450 40 220.291 110.145 55.073 39 225.939 112.970 56.485 37 238.152 119.076 59.538 32 275.363 137.682 68.841 31.5 279.734 139.867 69.934 30 293.721 146.860 73.430 27.8 316.965 158.483 79.241 27 326.357 163.178 81.589 24 367.151 183.576 91.788 23 383.114 191.557 95.779 21.5 409.843 204.922 102.461 17.3 509.343 254.671 127.336 15.4 572.184 286.092 143.046 13.3 662.528 331.264 165.632 11.6 759.623 379.812 189.906 10.6 831.286 415.643 207.821 9.6 917.878 458.939 229.469 5 1762.326 881.163 440.581 4.8 1835.756 917.878 458.939 4.7 1874.815 937.407 468.704 4.5 1958.140 979.070 489.535 Of course, not every device or display out there is exactly 8K UHD, 4K UHD, or Full HD (1080p). Here's another table with a number of popular devices with non-standard resolutions and their calculated PPI: PPIs for Popular Devices Device Size (in) Resolution (x/y) PPI Chromebook 11 11.6 1366x768 135.094 Chromebook Pixel 12.9 2560x1700 238.220 Chromebox 30 30 2560x1600 100.629 Dell Venue 8 8.4 1600x2560 359.390 Dell Venue 11 Pro 10.8 1920x1080 203.972 Essential Phone 5.71 2560x1312 503.786 Google Pixel 5 1080x1920 440.581 Google Pixel XL 5.5 1440x2560 534.038 Google Pixel 2 5 1920x1080 440.581 Google Pixel 2 XL 6 2880x1440 536.656 Google Pixelbook 12.3 2400x1600 234.507 HTC One M8/M9 5 1080x1920 440.581 iMac 27 27 2560x1440 108.786 iMac 5K 27 5120x2880 217.571 iPad 9.7 768x1024 131.959 iPad Mini 7.9 768x1024 162.025 iPad Mini Retina 7.9 1536x2048 324.051 iPad Pro 12.9 2732x2048 264.682 iPad Retina 9.7 1536x2048 263.918 iPhone 3.5 320x480 164.825 iPhone 4 3.5 640x960 329.650 iPhone 5 4 640x1136 325.969 iPhone 6 4.7 750x1334 325.612 iPhone 6 Plus 5.5 1080x1920 400.529 iPhone 7/8 4.7 1334x750 325.612 iPhone 7/8 Plus 5.5 1920x1080 400.528 iPhone X 5.8 2436x1125 462.625 LG G2 5.2 1080x1920 423.636 LG G3 5.5 1440x2560 534.038 MacBook 12 12 2304x1440 226.416 MacBook Air 11 11.6 1366x768 135.094 MacBook Air 13 13.3 1440x900 127.678 MacBook Pro 13 13.3 2560x1600 226.983 MacBook Pro 15 15.4 2880x1800 220.535 Nexus 10 10.1 2560x1600 298.898 Nexus 6 6 1440x2560 489.535 Nexus 6P 5.7 1440x2560 515.300 Nexus 9 8.9 2048x1536 287.640 OnePlus 5T 6.01 1080x2160 401.822 Samsung Galaxy Note 4 5.7 1440x2560 515.300 Samsung Galaxy Note 8 6.3 2960x1440 522.489 Samsung Galaxy S5 5.1 1080x1920 431.943 Samsung Galaxy S6 5.1 1440x2560 575.923 Samsung Galaxy S7 5.1 2560x1440 575.923 Samsung Galaxy S8 5.8 2960x1440 567.532 Samsung Galaxy S8+ 6.2 2960x1440 530.917 Sony Xperia Z3 Tablet 8 1920x1200 283.019 Sony Xperia Z4 Tablet 10.1 2560x1600 298.898 Surface 10.6 1366x768 147.839 Surface 2 10.6 1920x1080 207.821 Surface 3 10.8 1920x1080 203.973 Surface Book 13.5 3000x2000 267.078 Surface Pro 10.6 1920x1080 207.821 Surface Pro 3 12 2160x1440 216.333 Surface Pro 4 12.4 2736x1824 265.182 Don't worry if you didn't find your resolution or device. Remember, you can calculate how many pixels are in an inch for your device, no matter the size or resolution, using the math we described above. Was this page helpful? Thanks for letting us know! Get the Latest Tech News Delivered Every Day Email Address Sign up There was an error. Please try again. You're in! Thanks for signing up. There was an error. Please try again. Thank you for signing up. Tell us why! Other Not enough details Hard to understand Submit More from Lifewire What Pixels Are and What They Mean for TV Viewing All About 1080p FHD TVs Guide to Tablet Displays What Does 1080p Mean? 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