Do Straw Toppers Fit Stanley Cups? The Straw Buddy Fit Guide
"Will this fit my cup?"
That's the question we get more than any other about our straw toppers, so here's the whole answer in one place. Spoiler alert: if your straw is 10mm across or skinnier, you're probably good.
Which cups fit a straw topper? The quick answer
| Your cup | Fits? |
|---|---|
| Stanley Quencher (30/40oz) | Yes |
| Owala FreeSip | Yes |
| Starbucks cold cups | Yes |
| Hydro Flask straw lid | Yes |
| Simple Modern Trek | Yes |
| Reduce Cold1 | Yes |
| Smoothie straws | Yes |
| Yeti straw mugs | No |
| Brumate Era | No |
| Boba straws | No |
| McDonald's straws | No |
| Dunkin cups | Untested - be our guinea pig? |
The 10mm rule
Every Sip Sidekick slides onto your straw through an opening sized for 10mm - that's the width of a Stanley Quencher straw, and it's the most common size on big tumblers. There's a little flex in it, so skinnier straws work too: Starbucks cold cup straws (8mm), Hydro Flask (8mm), Owala (9-10mm) all hold just fine.
Wider is where it ends. Once a straw passes about 10.5mm, the topper won't slide over it. No amount of pushing changes the math.
The Stanley crowd: you're set
Stanley Quencher, Owala FreeSip, Simple Modern Trek, Reduce Cold1 - all in the fit zone. This is what our 3D printed straw buddies were built around, and it's where most of our customers live. Slide it down the straw, spin it to face whoever you want to make jealous, done.
Yeti and Brumate: sorry, no
Here's the honest version, because some shops fudge this one.
Yeti straw mug straws run about 11mm - just one millimeter wider than a Stanley straw. One millimeter doesn't sound like much, but the fit is snug on purpose (nobody wants a dragon sliding down their straw mid-sip), and that extra millimeter is the whole game. You'll see other sellers claim their straw toppers fit "Stanley AND Yeti." Ours don't, and we'd rather tell you now than in a return email.
Brumate isn't even close - their Era straws are 12mm. Boba straws (12-13mm) and McDonald's straws (up to 14mm, which is basically a pipe) are also out.
Dunkin: honestly, we haven't tested it
Dunkin doesn't publish their straw sizes anywhere we could find, and we won't guess in a fit guide. If you slide a Sidekick onto a Dunkin cup, tell us how it went - we'll update this post and credit you.
Cup not on the list? Grab a ruler
Measure across the fattest part of your straw. 10mm or under: your straw topper will fit. Skinnier than about 8mm: it'll hold, just a little loose. Wider than 10.5mm: it's a no, and we're sorry.
Ready to load up your straw? The whole crew of straw buddies is in the Sip Sidekicks collection - dragons, pets, cryptids, and everything in between, all 3D printed on our farm and shipped in days.