To print on one of the larger sizes, the photo must be of higher quality. The recommended dpi range is 150-300. If the resolution isn't high enough, the print will appear blurry or pixelated when enlarged. This isn't usually an issue with photos taken with a professional camera or with a newer smartphone.
Recommended Image Resolutions for 150 DPI
8"x10" Inches. 1200×1500 pixels
12"x12" Inches 1800×1800 pixels
11"x14" Inches. 1650×2100 pixels
12"x16" Inches. 1800×2400 pixels
12"x18" Inches 1800×2700 pixels
16"x16" Inches. 2400×2400 pixels
16"x20" Inches 2400×3000 pixels
16"x24" Inches 2400×3600 pixels
18"x24" Inches. 2700×3600 pixels
24"x24" Inches 3600×3600 pixels
24"x36" Inches. 3600×5400 pixels
32"x48" Inches 4800×7200 pixels
Recommended Image Resolutions for 300 DPI
8"x10" Inches. 2400×3000 pixels
12"x12" Inches. 3600×3600 pixels
11"x14" Inches. 3300×4200 pixels
12"x16" Inches. 3600×4800 pixels
12"x18" Inches. 3600×5400 pixels
16"x16" Inches. 4800×4800 pixels
16"x20" Inches. 4800×6000 pixels
16"x24" Inches. 4800×7200 pixels
18"x24" Inches 5400×7200 pixels