Quick answer
Standard cribs in the US use a fitted cot sheet with a mattress size of 52 inches long by 28 inches wide, with a pocket depth of 5 to 8 inches. Always check the sheet's elastic quality and depth range to ensure a snug, safe fit.
Why fit matters for safe sleep
A loose fitted sheet can bunch up and create a suffocation risk, while one that's too tight may pull on the mattress corners and leave gaps. The goal is a sheet that stays in place without needing constant adjustment.
Organic cotton jersey blends, like those used in Fox & Fallow's 2026 collection, offer natural stretch that helps the sheet conform to the mattress without sagging. This stretch is especially helpful if your mattress has a thicker pad or topper.
Measuring your crib mattress
Before buying, measure the length, width, and thickness of your mattress. Standard crib mattresses are 52 x 28 inches, but thickness can vary from 4 to 8 inches depending on the model and age.
If your mattress is on the thinner side (under 5 inches), a sheet with a deep pocket may not grip tightly enough. Conversely, a mattress over 7 inches thick needs a sheet with a generous pocket depth and strong elastic to prevent slipping.
How to choose the right fitted cot sheet size
- 1. Measure your mattress: Use a tape measure to get the length, width, and thickness of your crib mattress. Write these down before shopping. Standard size is 52 x 28 inches, but thickness varies.
- 2. Check pocket depth range: Look for sheets that list a depth range (e.g., 5–8 inches). Choose one that covers your mattress thickness with a little room to spare. A sheet that's too shallow won't stay on; one too deep may feel loose.
- 3. Prioritize elastic quality: Full elastic bands around the entire sheet perimeter provide the most secure fit. Avoid sheets with elastic only at the corners. All-around elastic prevents the sheet from popping off during movement.
- 4. Consider fabric stretch: Organic cotton jersey blends naturally stretch, making them easier to install and more forgiving of minor mattress thickness variations. Stretch fabrics conform better than non-stretch woven cottons.
Sheet options that fit
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Golden Pears Organic Fitted Cot Sheet: Made from a super soft and stretchy organic cotton jersey blend that's GOTS and Oeko-Tex Standard 100 certified. The stretchy jersey blend helps the sheet hug standard crib mattresses securely, reducing the chance of bunching during sleep.
Golden Pears Organic Fitted Cot Sheet
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Sage Stripe Organic Fitted Cot Sheet: High quality, machine washable, and part of the new 2026 collection with the same organic cotton jersey construction. Machine washability makes it easy to keep the sheet clean, and the same stretchy material ensures a consistent fit wash after wash.
Sage Stripe Organic Fitted Cot Sheet
Is this guide for you?
Best for
- Parents buying a fitted sheet for a standard US crib mattress (52 x 28 inches)
- Shoppers looking for organic, safe materials and a snug fit
Not for
- Mini cribs, bassinets, or portable play yard mattresses with non-standard dimensions
- Mattresses thicker than 8 inches (may need a specialty deep-pocket sheet)
