Calendar photo check: will it print sharp?
Whether a photo prints sharp is arithmetic: pixels, divided by the inches they have to cover, after the photo is cropped to fit. This runs our photo calendar guide’s 300-pixels-per-inch line against the photo you actually picked and the place it’s going. It can’t judge focus, light or whether it’s the right photo for March — only whether there are enough pixels for the size.
Once each month has a photo that passes
Photo Calendar picks the twelve, then sends them where you checked them for
- The checker says which photos are big enough. Photo Calendar starts one step earlier: it reads when each photo was taken and suggests a cover for every month.
- Swap the ones that came up short. Tap a month and choose another photo; the colour palette and note change to match it.
- Then print it, or put it on your phone. A 12-page 300 dpi PDF for A4 or A5, or the month at your screen’s exact resolution as a Lock Screen wallpaper. The Home Screen widget is free and turns the page on the 1st.
How this works
A calendar layout, a wallpaper and a widget all fill their space: the photo is scaled until there’s no gap, and whatever hangs over the edge is cut off. So the checker does the same. It crops your photo to the shape of the slot, counts the pixels left, and divides by the size they have to cover. For paper that gives pixels per inch; for a screen, how many photo pixels land on each screen pixel.
There’s one line, the guide’s 300 ppi, and the checker doesn’t invent a second “good enough” one under it. A photo below the line is told by how much, the largest size it would be sharp at, and which other calendar size it already suits.
The crop is the part people miss. “Any recent iPhone photo is big enough” is true of the pixel count, but a landscape photo turned to fill a portrait page loses more than half its width — a 4032 × 3024 shot lands near 258 ppi on a full A4 page and over 480 ppi above the dates. When that’s what’s happening, the answer says “big enough, wrong shape” rather than blaming the photo.
Where the numbers come from
The 300 ppi line, the A4 pixel size and the list of what prints soft are from Step 4 of how to make a photo calendar on iPhone. The screen sizes are from how to make a calendar wallpaper, and the widget sizes from how to add a photo calendar widget.
| Slot | Pixels needed | Source |
|---|---|---|
| A4 page, 210 × 297 mm | 2480 × 3508 | the guide |
| A5 page, 148 × 210 mm | 1748 × 2480 | same 300 ppi, our arithmetic |
| US Letter, 8.5 × 11 in | 2550 × 3300 | same 300 ppi, our arithmetic |
| Photo above the dates | the page width × half its height | the guide’s “roughly half”, our estimate |
| iPhone 15 or 16 screen | 1179 × 2556 | the wallpaper guide |
| Plus or Pro Max, or not sure | 1320 × 2868 | the top of the wallpaper guide’s range |
| Medium / large widget | screen width × half / all of it | our estimate from the 4×2 and 4×4 grids |
Two of those rows are ours and are labelled that way. Real layouts put the photo in slightly more or less than half the page, and a widget is a little narrower than the screen; both estimates err towards needing more pixels, not fewer.
If you’re not sure, assume you need more
The two mistakes cost different amounts. Being told a photo is fine when it isn’t costs a print, or twelve, and you find out on the wall. Being told it’s short when it would have passed costs a minute choosing another photo. So where the checker has to guess, it guesses high: an unknown iPhone is judged on the largest screen, ppi is rounded down, and the photo is always cropped to fill, never shrunk to fit with borders.
If a photo you care about comes up short, look for its original before giving up on it. A picture someone sent you in a chat, or one you screenshotted, is usually a smaller copy of a file that exists somewhere at full size.
- How to make a photo calendar on iPhone — the guide this comes from: picking a photo per month, where the calendar goes, and printing it
- How to make a calendar wallpaper for your Lock Screen — the screen sizes, and the parts of the screen to keep clear of the clock
- How to add a photo calendar widget on iPhone — which widget size to choose, and why landscape photos suit the medium one