How to change the DPI of an image
- Drop one or more JPG or PNG files on the box above. The table shows each file's pixel size, its current DPI and how large it would print.
- Choose a DPI: click 300 or 600, or type any value.
- Leave the mode on Change DPI only for printers, publishers and forms that just check the DPI value. Use Resample only if you must keep the printed size and change the pixel count.
- Download each file, or all of them. File names end in
-300dpiso you can tell them apart.
Change DPI only vs resample
DPI (dots per inch) is a number stored in the image file that tells a printer how many of the image's pixels to place in one inch of paper. It has no effect on screen. The same 3000 × 2000 px photo prints at 10 × 6.67 inches when tagged 300 DPI and at 41.7 × 27.8 inches when tagged 72 DPI — same pixels, different paper size.
- Change DPI only rewrites the resolution fields in the header: the JFIF density and EXIF
XResolution/YResolutionin a JPG, or thepHYschunk (plus theeXIfresolution that iPhone and Mac PNGs carry) in a PNG. The compressed image data is copied byte for byte, so there is no generation loss and your camera EXIF (date, GPS, camera model) stays in place. This is what “convert to 300 DPI” requests almost always mean. - Resample keeps the printed size and changes the number of pixels. Going from 72 to 300 DPI multiplies each side by 4.17, so a 1000 px wide image becomes 4167 px. That makes a much larger file and looks soft, because the browser has to invent the new pixels. Use it when a print shop insists on both a physical size and a pixel count.
DPI and print size table
Pixels needed = size in inches × DPI (1 inch = 2.54 cm). Use this to check whether a photo is big enough before you set the DPI.
| Print size | 72 DPI | 150 DPI | 300 DPI | 600 DPI |
|---|---|---|---|---|
| Passport photo 35 × 45 mm | 99 × 128 | 207 × 266 | 413 × 531 | 827 × 1063 |
| US passport 2 × 2 in (51 × 51 mm) | 144 × 144 | 300 × 300 | 600 × 600 | 1200 × 1200 |
| Wallet 2.5 × 3.5 in | 180 × 252 | 375 × 525 | 750 × 1050 | 1500 × 2100 |
| 4 × 6 in (10 × 15 cm) | 288 × 432 | 600 × 900 | 1200 × 1800 | 2400 × 3600 |
| 5 × 7 in (13 × 18 cm) | 360 × 504 | 750 × 1050 | 1500 × 2100 | 3000 × 4200 |
| 8 × 10 in (20 × 25 cm) | 576 × 720 | 1200 × 1500 | 2400 × 3000 | 4800 × 6000 |
| A4 210 × 297 mm | 595 × 842 | 1240 × 1754 | 2480 × 3508 | 4961 × 7016 |
| US Letter 8.5 × 11 in | 612 × 792 | 1275 × 1650 | 2550 × 3300 | 5100 × 6600 |
| A3 297 × 420 mm | 842 × 1191 | 1754 × 2480 | 3508 × 4961 | 7016 × 9921 |
Pixels to inches and cm at 72, 150, 300 and 600 DPI
| Pixels | 72 DPI | 150 DPI | 300 DPI | 600 DPI |
|---|---|---|---|---|
| 600 px | 8.33 in / 21.17 cm | 4.00 in / 10.16 cm | 2.00 in / 5.08 cm | 1.00 in / 2.54 cm |
| 1080 px | 15.00 in / 38.10 cm | 7.20 in / 18.29 cm | 3.60 in / 9.14 cm | 1.80 in / 4.57 cm |
| 1920 px | 26.67 in / 67.73 cm | 12.80 in / 32.51 cm | 6.40 in / 16.26 cm | 3.20 in / 8.13 cm |
| 3000 px | 41.67 in / 105.83 cm | 20.00 in / 50.80 cm | 10.00 in / 25.40 cm | 5.00 in / 12.70 cm |
| 4032 px (12 MP phone) | 56.00 in / 142.24 cm | 26.88 in / 68.28 cm | 13.44 in / 34.14 cm | 6.72 in / 17.07 cm |
Worked examples
A print shop asks for “300 DPI” for a 4×6 photo
Your phone photo is 4032 × 3024 px and tagged 72 DPI. At 300 DPI it prints 13.44 × 10.08 in — comfortably larger than 6 × 4, so the image already has enough pixels. Set 300 in Change DPI only mode and send the file; the lab will scale it down to 6 × 4. No resampling needed.
A logo must be 600 DPI at 2 inches wide
2 in × 600 DPI = 1200 px. If your logo is 1500 px wide, set 600 DPI and it prints 2.5 in wide — fine. If it is only 400 px wide, a 600 DPI tag makes it print 0.67 in wide. Resampling to 1200 px will pass a DPI checker but will look blurry; ask for the original vector file (SVG, AI, PDF) instead.
A scanned signature at 72 DPI for a form that says “minimum 200 DPI”
Most online forms only read the DPI value. If the scan is sharp and large enough (for example 600 × 200 px), setting 200 DPI changes only the tag and the file passes. If it is tiny, rescan at 200–300 DPI instead.
DPI, PPI and “resolution”
Strictly, PPI (pixels per inch) describes an image and DPI (dots per inch) describes a printer's ink dots, but software, forms and print shops use DPI for both, and the value stored in a JPG or PNG is the same number. “Resolution” can mean either the pixel dimensions (1920 × 1080) or the DPI tag, which is why a “DPI converter resolution” search can mean either task: this page changes the DPI tag; to change pixel dimensions use the image resizer.
How to check an image's DPI
- Here: drop the file above — the “Current DPI” column shows the value and where it was read from (JFIF, EXIF or pHYs). Screenshots and many web images have no DPI tag at all; programs then assume 72 or 96.
- Windows: right-click the file → Properties → Details → Horizontal resolution / Vertical resolution.
- Mac: open in Preview → Tools → Show Inspector → Image DPI.
- All metadata: the image metadata viewer shows the EXIF resolution fields along with camera and GPS data.
FAQ
How do I convert an image to 300 DPI?
Drop the JPG or PNG into the converter, choose 300, keep the mode on Change DPI only, and download. The file gets a 300 DPI tag in its header while every pixel stays the same. Check the print size shown: if it is smaller than you need, the image does not have enough pixels for that size at 300 DPI.
Does changing DPI reduce quality?
Not in Change DPI only mode. The tool edits a few bytes in the file header (JFIF density, EXIF resolution or the PNG pHYs chunk) and leaves the compressed image data untouched, so the pixels are bit-for-bit identical. Resample mode does change pixels, because it enlarges or shrinks the image.
How many pixels do I need for a 4 × 6 inch print at 300 DPI?
Multiply each side in inches by the DPI: 4 × 300 = 1200 and 6 × 300 = 1800, so 1200 × 1800 pixels. A 5 × 7 inch print needs 1500 × 2100 pixels and an A4 page needs 2480 × 3508 pixels at 300 DPI.
Will increasing DPI make a blurry photo sharp?
No. DPI only tells a printer how many pixels to fit into each inch. A small or blurry image stays the same; setting a higher DPI just makes it print smaller. Resampling to more pixels makes the file bigger but cannot add real detail.
When should I use 600 DPI instead of 300?
Use 600 DPI for line art, logos, fine text, signatures and scans you want to archive or enlarge later. Photos rarely benefit beyond 300 DPI. If a printer, publisher or form explicitly asks for 600 DPI, set it here; the print size halves compared with 300 DPI.
What DPI should images be for websites or Instagram?
DPI is ignored on screens; only pixel dimensions matter. A 1080 × 1350 image looks the same on Instagram whether it is tagged 72 or 300 DPI. Resize to the pixel size the platform wants instead.
How do I check the DPI of an image?
Drop it into this tool, which reads the DPI from the JFIF, EXIF or PNG header. On Windows, right-click the file, choose Properties, then Details, and look at Horizontal resolution. On a Mac, open it in Preview and choose Tools, Show Inspector.