Stainless Steel Straw Size Guide
You bought a beautiful set of reusable metal straws. Then you reached for your Stanley Quencher and the straw was two inches too short. Sound familiar? This guide fixes that — for every cup you own.
Straw sizing is the most overlooked detail in the reusable straw world — and it's the #1 reason people give up on metal straws before they've given them a fair shot. We're going to match every common cup, tumbler, and glass in your kitchen to the exact straw it needs, so you never have the wrong straw again.
The Quick-Reference Size Chart
Bookmark this. It covers every cup and tumbler you're likely to own, with the exact straw specs for each.
| Cup / Tumbler | Length | Diameter | Best Style |
|---|---|---|---|
| Wine glass / rocks glass | 6.25" (160mm) | 6mm or 8mm | Short straight |
| 12 oz tumbler / kids cup | 8.5" (215mm) | 6mm | Regular straight or bent |
| 20 oz Yeti / Hydro Flask | 8.5" (215mm) | 6mm | Regular straight or bent |
| Smoothie / protein shake cup | 8.5"–9.5" | 8mm | Wide straight or bent |
| Boba / bubble tea cup | 8.5" (215mm) | 12mm | Exta-Wide straight |
| Mason jar (pint / 16 oz) | 8.5" (215mm) | 6mm or 8mm | Regular straight |
| Iced coffee cup (tall takeout) | 9"–9.5" (241mm) | 6mm | Long bent |
How to read this chart: "Length" determines whether the straw clears the top of your cup. "Diameter" determines what you can drink through it — 8mm wide bore is essential for thick smoothies and 12mm straws work well for boba. "Style" refers to straight vs. bent tip. Bent straws work best with lids; straight straws work best for open glasses. It's always a good idea to double check you cup measurements and straw needs before placing an order.
The Two Numbers That Actually Matter: Length & Diameter
Every straw has two measurements — length and diameter — and both matter. Here's how to think about each one.
- 160mm (6.25") Short: Designed for rocks glasses, wine tumblers, and low-profile cups. The straw that fits where every other straw is too tall.
- 215mm (8.5") Regular: The workhorse length. Fits most 12–20 oz tumblers, pint glasses, mason jars, and standard cocktail glasses.
- 241mm (9.5") Long: Made for tall cups — 30 oz and 40 oz Stanley, Yeti, RTIC, and tall iced coffee cups. The straw that finally reaches.
- 6mm Standard Diameter: Works for water, juice, iced tea, coffee, cocktails, and most everyday drinks.
- 8mm Wide Bore: Essential for thick smoothies, and protein shakes. If you've ever struggled to drink a smoothie through a thin straw, this is the answer.
- 12mm Extra-Wide Bore: Essential for thick smoothies, protein shakes, acai bowls, and bubble tea. Easily get those delicious tapioca pearls with this option.
Cup-by-Cup Breakdown: The Most Popular Tumblers
Here's the detail behind the chart for the cups we get asked about most.
- Yeti Rambler (20 oz): A 215mm regular straight or bent straw is the perfect fit. For the 20 oz Yeti, step up to 241mm — the extra cup height needs the extra straw length.
- Hydro Flask (20 oz Tumbler): 215mm regular straw works great. For 30 oz wide mouth bottles, go 241mm straight — wide mouth openings suit a straight straw better than a bent one.
- RTIC Tumbler (20 oz & 30 oz): Same logic as Yeti. 215mm for 20 oz, 241mm for 30 oz.
- Mason Jar / Pint Glass (16 oz): 215mm regular straight or bent. It sits perfectly above the rim without towering over the glass.
- Rocks Glass / Wine Tumbler: The 160mm short straw is the one most people overlook — and the one that makes all the difference for low-profile glassware.
"If you've ever struggled to drink a thick smoothie through a thin metal straw, an 8mm wide-bore straw is the answer you've been looking for."
Bent vs. Straight: A Simple Decision Rule
Once you have the right length and diameter, the only remaining choice is straight vs. bent. Here's the easy rule.
- Choose bent if: You're using a tumbler with a lid, drinking while on the go, drinking straight from the can such as soda or sparkling water, or using it in an iced coffee cup or travel mug. The angled tip makes sipping more natural without having to tip the cup.
- Choose straight if: You're drinking from an open glass, using a bottle with a straw opening, or drinking smoothies. Straight straws are also marginally easier to clean with a brush.
Cleaning tip: Clean your straw immediately after use while residue is still wet. Both sizes are fully dishwasher safe — or run the included nylon brush through under warm water with a drop of dish soap. Done in 10 seconds. Dried smoothie in a narrow straw is the only scenario that takes more than a quick rinse.
Still not sure which straw you need? The simplest solution is our Ultimate Multi-Size Stainless Steel Straw Set — nine straws covering every length, diameter, and style, plus two cleaning brushes and a linen carrying bag. Every cup covered. Once and for all.
Stop Guessing. Get the Right Straw for Every Cup.
The Ultimate Multi-Size Set includes 9 straws — every length, diameter, and style — starting at just $14.99.
Shop the Full Set