How many megapixels do I need for a large print?

12MP is sufficient for A4 at 300 DPI. 24MP covers A3 at 300 DPI or A2 at 200 DPI. 45MP handles A2 at 300 DPI. 100MP covers A1 at 300 DPI. For larger prints, remember viewing distance increases, so lower DPI is acceptable.

Does aspect ratio affect print size?

Yes. A 24MP camera with 3:2 aspect gives 6000x4000px. With 4:3 it gives 5657x4243px. The wider aspect ratio gives a slightly wider but shorter print. When printing to standard paper sizes, you may need to crop, losing some megapixels.

Can I print larger than the maximum size?

Yes, but quality reduces. Printing larger than your native DPI means pixels are stretched (interpolated). Modern printers and AI upscaling do this well. A 24MP image upscaled 2x to 96MP can print at A1 with good results. Sharpness and detail in the original matter more than raw megapixels.

What are standard UK print sizes?

Common UK sizes: 6x4 inches (15x10cm), 7x5 inches (18x13cm), A4 (29.7x21cm), A3 (42x29.7cm), A2 (59.4x42cm), A1 (84.1x59.4cm), A0 (118.9x84.1cm). Photo labs also offer custom sizes.

PhotoCalcs

Megapixel to Print Calculator — Maximum Print Sizes

Find maximum print sizes for your camera megapixel count at various DPI settings.

Megapixels

Camera resolution

Aspect RatioSensor aspect ratio

How We Calculate This

This calculator derives pixel dimensions from megapixels and aspect ratio:

Pixel Dimensions

Width = √(megapixels x 1,000,000 x aspect ratio)

Print Size

Print (cm) = (pixels / DPI) x 2.54

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates based on standard optical and photographic formulas. Results may vary with specific equipment.