How to Change DPI in Affinity Photo

Method 1 — Change DPI Metadata Only (No Pixel Change)

Affinity Photo lets you update the DPI tag stored in a document without altering a single pixel. Open your image, then navigate to Document > Document Setup (keyboard shortcut: Cmd+Shift+D on Mac, Ctrl+Shift+D on Windows). The dialog shows the current DPI field — type 300 and click OK.

This operation changes the print-dimension hint embedded in the file. The pixel count stays identical, so a 1500 × 1200 pixel image at 72 DPI becomes a 1500 × 1200 pixel image at 300 DPI — it will now print at 5 × 4 inches instead of 20.8 × 16.7 inches. Use this method when your image already contains enough pixels for the target print size and you only need to correct the metadata.

• Shortcut: Cmd+Shift+D (Mac) / Ctrl+Shift+D (Windows)
• Change the DPI field to 300, then click OK
• Pixel count remains unchanged — only the print dimension hint updates
• Use case: correct DPI metadata on an image that already has sufficient pixels

Method 2 — Resize Document with Resampling (Adds Pixels)

When your image lacks enough pixels to print at 300 DPI at the target size, Affinity Photo can add pixels through resampling. Navigate to Document > Resize Document, then check the Resample checkbox. Set the Resolution field to 300 DPI and enter your physical dimensions — for example, 8 × 10 inches. Affinity Photo calculates the required pixel count (2400 × 3000 pixels) and generates those pixels using the selected algorithm.

Choose the resampling algorithm based on your image content:

• Bilinear — fast processing, produces soft results; suitable for quick web previews
• Bicubic — better edge preservation for photographs; good general-purpose choice
• Lanczos 3 (non-separable) — sharpest output; recommended for print upscaling of photographic images
• Nearest Neighbor — preserves hard pixel edges; use for pixel art, icons, or screenshots

After setting the algorithm, click Resize. Affinity Photo adds pixels to meet the 300 DPI × dimension requirement. Save a copy before resampling — the original cannot be recovered from the resampled file.

Exporting at 300 DPI in Affinity Photo

Affinity Photo offers granular DPI control at export, independent of the document DPI. Open the export dialog via File > Export, select TIFF or JPEG as the format, then expand the More panel to reveal the Resolution field. Set it to 300 DPI before clicking Export.

• Select TIFF as the format for archival print masters — use 16-bit depth for maximum tonal range
• Select JPEG at quality 90 or higher for consumer lab printing (Shutterfly, Nations Photo Lab)
• The export Resolution field overrides document DPI for the exported file only — the working document DPI is unchanged
• For commercial offset printing: check with the print shop whether they require CMYK; Affinity Photo exports sRGB by default

If you need to confirm the final file DPI before submitting to a printer, use the DPI calculator at /dpi-calculator to verify pixel dimensions against your target print size.

Checking Current DPI in Affinity Photo

Affinity Photo displays DPI information in two places. The most direct route is Document > Document Setup, which shows the current DPI in the Resolution field. The Document Units panel in the toolbar shows pixel dimensions and DPI side by side for a quick reference without opening a dialog.

• Document > Document Setup — shows current DPI numerically
• Document Units panel in toolbar — displays pixel dimensions and DPI together
• Hover over the canvas size indicator in the status bar for a quick pixel read
• Use the DPI calculator to compute effective DPI from pixel dimensions and your target print size

Common DPI Mistakes in Affinity Photo

Several DPI errors appear consistently in Affinity Photo workflows. Recognizing them before sending files to a printer saves time and reprint costs.

• Changing DPI in Export without resampling the document: the exported file carries 300 DPI metadata but the original pixel count. A 1500 × 1200 pixel file at 300 DPI prints at 5 × 4 inches — smaller than expected and potentially blurry at larger sizes.
• Using Bilinear resampling for sharp text or line art: Bilinear blurs hard edges. Use Nearest Neighbor for screenshots or diagrams with crisp pixel boundaries.
• Forgetting color space on export: Affinity Photo exports sRGB by default. Commercial offset printers require CMYK. Convert the color space before export: Document > Convert ICC Profile and select a CMYK profile such as US Web Coated (SWOP) v2.
• Skipping the .afphoto master backup: resampling is destructive. Save the native .afphoto file before resizing so you retain the original pixel data.

Affinity Photo vs Photoshop DPI Workflow

Affinity Photo and Photoshop handle DPI changes through parallel workflows. In Photoshop, the equivalent of Affinity Photo's Resize Document is Image > Image Size, with the Resample checkbox controlling whether pixels are added. Both applications change only the metadata when Resample is unchecked.

• Affinity Photo uses Lanczos 3 for print upscaling; Photoshop offers Preserve Details 2.0 (AI-enhanced). Both produce high-quality results for moderate upscaling (up to 2×).
• Affinity Photo applies changes non-destructively through live filters — keep the .afphoto master file before resampling.
• Photoshop has Smart Objects, which allow embedding a low-res placeholder and re-linking a high-res file later — Affinity Photo lacks a direct equivalent.
• Affinity Photo costs a one-time fee; Photoshop requires a subscription. For most 300 DPI print preparation tasks, Affinity Photo delivers identical results at a lower cost.

For quick DPI conversion without opening any desktop app, use the convert to 300 DPI tool at /convert-to-300-dpi to process images directly in your browser.