A standard 20 oz stainless steel tumbler is a versatile, mid-sized vessel designed for both hot and cold beverages.1 It is widely considered the "gold standard" size because it provides enough capacity for a large coffee or tea while remaining portable and easy to hold.2
 
Key Specifications
Dimensions: Usually about 6.5 to 8 inches tall with a 3-inch diameter at the top.
Base Design: Most are tapered at the bottom to ensure they fit into standard car cup holders.3
 
Material: Constructed from 18/8 food-grade stainless steel, which is rust-resistant and BPA-free.4
 
Insulation: Features double-wall vacuum insulation.5 This creates a thermal barrier that:
 
Keeps drinks cold for 12–24 hours.6
 
Keeps drinks hot for 6–12 hours.
Prevents "sweating" (condensation) on the exterior.7
 
Common Features
Feature
Description
Lid Type
Usually a clear, splash-resistant press-in lid or a sliding closure. Many are straw-compatible.
Finish
Often finished with a powder coating for a slip-resistant grip and added durability against scratches.
Cleaning
Most modern versions are dishwasher safe, though hand-washing is often recommended to preserve the vacuum seal long-term.
Taste
The high-quality steel ensures no flavor transfer, so your water won't taste like the coffee you had earlier.