FUNtainer Water Bottle Sizes: 12oz vs 16oz for Kids
By Thermos Brand | Published: 2026-10-16
Category: Buying Guides
Choose the right FUNtainer size for your child: 12oz for little hands and short outings, 16oz for bigger kids and full school days. Here's how to decide.
Quick answer
For most kids under 6, the 12oz FUNtainer is the better fit: lighter, easier to carry, and enough for a half-day or short outing. For kids 7 and up who need hydration through a full school day or sports practice, the 16oz FUNtainer with locking lid holds more and resists accidental opening in a backpack. If your child is between sizes, start with 12oz for daily use and add a 16oz for longer days.
Why size matters more than you think
A water bottle that's too big gets left in the car or weighs down a little shoulder. One that's too small runs dry by lunch and gets refilled with whatever's available—often juice or soda. The right size keeps water the easy choice. FUNtainer bottles come in two kid-friendly sizes: 12oz and 16oz. Both keep drinks cold for up to 12 hours with double-wall vacuum insulation, so the difference isn't temperature—it's capacity, weight, and how your child uses it.
12oz FUNtainer: best for little hands and short days
The 12oz size is the classic preschool and early elementary bottle. It's light enough for a 3- or 4-year-old to carry by the integrated soft-touch handle, and the push-button lid covers the silicone straw when it's not in use—a small but real hygiene win when bottles get dropped on the playground. It's also dishwasher safe (top rack only) and BPA-free.
Capacity-wise, 12oz covers a morning at preschool, a half-day camp, or a quick trip to the park. For a full school day, many parents send two 12oz bottles or refill at lunch. If your child is still learning to open and close a lid independently, the 12oz straw lid is easier to manage than a spout.
16oz FUNtainer: best for older kids and full schedules
The 16oz FUNtainer is sized for older kids, tweens, and teens who need more water between refills. The key upgrade is the push-button locking spout lid, which prevents accidental opening in a backpack—a common cause of soggy homework. It's still double-wall stainless steel, BPA-free, and dishwasher safe on the top rack.
This size suits a full school day, practice, or a hike. It's heavier when full (about 1.5 pounds with water), so it's not the best first bottle for a toddler. But for a 7-year-old who's tired of asking for refills, the extra 4 ounces make a noticeable difference.
How much water does your child actually need?
General guidance suggests about 5 cups (40oz) of total daily fluids for 4- to 8-year-olds, and 7 to 8 cups (56–64oz) for 9- to 13-year-olds—but that includes water from food and other drinks. A 12oz bottle refilled twice covers a good chunk of the younger range; a 16oz bottle refilled twice covers most of the older range. Use these numbers as a rough starting point, not a strict rule. Activity level, weather, and individual needs vary.
Decision rules: pick the right FUNtainer size
- Child's age: Under 6: choose 12oz. Age 7 and up: choose 16oz. If your child is 6, consider how much they carry and whether they have access to a refill. Age is the fastest filter, but not the only one.
- Length of day: Half-day or outings under 3 hours: 12oz is enough. Full school day or sports practice: 16oz reduces refill trips. Match capacity to time away from a sink.
- Lid type: Straw lid (12oz) is easier for little kids. Locking spout lid (16oz) prevents spills in backpacks. Choose the lid that fits your child's routine, not just the size.
- Weight when full: A full 12oz bottle weighs about 1 pound; a full 16oz bottle weighs about 1.5 pounds. Test-carry a similar weight before buying for a small child. If your child complains about a heavy backpack, size down.
FUNtainer sizes at a glance
- 12oz FUNtainer® Water Bottle Paw Patrol: 12oz FUNtainer Water Bottle Paw Patrol keeps drinks cold for up to 12 hours, has a push-button lid with silicone straw, and an integrated soft-touch carry handle. Light and easy for younger kids to carry and open independently; the straw lid is familiar and hygienic.
- 16oz FUNtainer® Water Bottle Patterns with Locking Lid: 16oz FUNtainer Water Bottle Patterns with Locking Lid keeps drinks cold for up to 12 hours and has a push-button locking spout lid to prevent accidental opening in backpacks. More capacity for older kids and a locking lid that avoids leaks in a school bag.
- 12oz FUNtainer® Water Bottle Penguin: 12oz FUNtainer Water Bottle Penguin keeps drinks cold for up to 12 hours and has a push-button lid covering a silicone straw. A lower-cost 12oz option with the same insulation and easy-carry handle.
Who should buy which size
Best for
- Preschoolers and early elementary kids (ages 3–6) who need a light, easy-to-carry bottle for half-days and short outings
- Parents who want a simple straw lid their child can open without help
- Older kids and teens (ages 7+) who need more water through a full school day, practice, or trail
- Families who want a locking lid to prevent backpack leaks
Not for
- Toddlers who still throw or lose bottles frequently—choose a smaller, simpler cup
- Kids who need more than 32oz between refills—consider a larger non-FUNtainer bottle
- Anyone looking for a bottle that fits in a standard cup holder—check dimensions first
