Owala vs Stanley in the UK: Sizes in ml, Lids and Colours Compared
Short answer: pick an Owala FreeSip if you want a lockable, leak-proof bottle that can ride in a bag; pick a Stanley Quencher if you want a big handled tumbler with a straw for the desk or car. Owala's "40 oz" is 1.18 litres.
Both brands sell their bottles in US fluid ounces, which is why so many UK shoppers end up searching for "Owala FreeSip 40 oz" or "Stanley 30 oz" and then wondering how big that actually is. This guide converts every common size into millilitres, explains how the lids really differ, and helps you choose a colour and model for yourself or as a gift. It builds on our general insulated water bottle guide, which covers how vacuum insulation works and how to keep a steel bottle clean.
Owala vs Stanley at a glance
| Model | Sizes (US oz → ml) | Lid and drinking style | Maker's cold claim | Dishwasher | Best for |
|---|---|---|---|---|---|
| Owala FreeSip | 24 oz (710 ml), 32 oz (946 ml), 40 oz (1.18 L) | Push-button lid with built-in straw or wide swig spout; carry loop doubles as a lock | 24 hours cold | Lid top rack; hand-wash body recommended | Bags, commuting, school, gym |
| Owala FreeSip Sway | 18 oz (532 ml), 30 oz (887 ml), 40 oz (1.18 L), 64 oz (1.89 L) | Same FreeSip spout, plus a bucket handle and a contoured, cup-holder-friendly body | 24 hours cold | Lid only; hand-wash cup | Car journeys and all-day sipping |
| Stanley Quencher H2.0 FlowState | 20 oz (0.59 L), 30 oz (0.89 L), 40 oz (1.18 L), 64 oz (1.9 L) | Rotating cover with three positions: straw, drink opening, full cover; side handle | 1.18 L: 11 hours cold, 48 hours with ice | Dishwasher safe | Desk, car cup holder, home |
| Stanley IceFlow 2.0 and ProTour | Mostly 30 oz (887 ml) and 40 oz (1.18 L), plus smaller sizes | Flip-up straw that snaps shut; described as leak-resistant | Varies by model | Check the listing | People who want a straw tumbler that travels better |
Sizes and claims above come from Owala's FreeSip and FreeSip Sway product pages and Stanley's Quencher H2.0 FlowState 1.18 L page. Insulation figures are the manufacturers' own and depend on how full the bottle is, how much ice you add and the room temperature.
Sizes: converting ounces to millilitres
One US fluid ounce is about 29.6 ml, which is slightly more than a UK fluid ounce, so a quick mental "times 30" gets you close. Here are the sizes you will see most often on Owala and Stanley listings:
- 16 oz = 473 ml – the Owala FreeSip Kids size. Light enough for a school bag and small hands.
- 20 oz = about 590 ml – a compact Stanley Quencher or flip-straw size; similar to a large takeaway coffee.
- 24 oz = 710 ml – the most popular Owala FreeSip size. Fits most bag side pockets and many car cup holders.
- 30 oz = 887 ml – the "middle" Stanley Quencher and FreeSip Sway size. Roughly one refill gets most people through a working day.
- 32 oz = 946 ml – just under a litre. A good gym or long-walk size for the standard FreeSip.
- 40 oz = 1.18 litres – the headline Stanley Quencher size, and the largest standard FreeSip. If you searched for "Owala FreeSip 40 oz", this is it.
- 64 oz = about 1.9 litres – a jug-sized option for long days out.
Two practical points. First, a full 1.18-litre steel bottle is heavy – well over a kilogram once filled – so think about whether it will live on a desk or be carried around. Second, height matters more than you might expect: tall 40 oz FreeSip bottles will not fit every cup holder, which is exactly the problem the tapered Sway and the narrow-based Quencher are designed to solve. Stanley says its Quencher's narrow base "fits just about any car cup holder".
Lids: the real difference between the two
Owala FreeSip: built for bags
The FreeSip lid is the reason most people choose Owala. Press the button and the lid flips open to reveal one spout with two ways to drink: sip upright through the built-in straw, or tilt the bottle back and swig from the wider opening. Owala describes the lid as leak-proof, and the hinged carry loop folds down over the button to lock it, so the bottle can go in a rucksack or handbag with less worry. Owala's own care advice is that the lid is top-rack dishwasher safe, the straw can go in the cutlery basket, and the cup itself is best washed by hand to protect the finish.
Stanley Quencher H2.0: built for sipping all day
The Quencher is a tumbler rather than a sealed bottle. Its FlowState lid rotates between a straw opening, a drink opening and a full-cover top. Stanley says the straw opening is "designed to resist splashes", which is not the same as being leak-proof, so a Quencher is happiest upright – on a desk, beside the sofa or in a car cup holder. In return you get a comfortable side handle, easy access with one hand and a body that Stanley lists as dishwasher safe.
Stanley IceFlow and ProTour: the middle ground
If you like Stanley's look but need something that copes better with travel, the flip-straw models are worth a look. The straw flips up to drink and snaps down to close, and both the IceFlow 2.0 and the ProTour are described in their listings as leak-resistant rather than leak-proof. The ProTour listing also notes it is for cold drinks only.
Hot drinks, fizzy drinks and what not to put inside
Owala's FreeSip page is clear that the bottle should not be used with hot, carbonated or perishable liquids. Pressure from hot or fizzy drinks can force liquid out through a straw-style spout, and milky drinks left in a closed bottle go off quickly. The same common-sense rule applies to straw tumblers from any brand. If you want something for tea or coffee, look at a travel tumbler with a sliding or flip lid instead, such as the Owala SmoothSip Slider 591 ml, and check the product description says it is suitable for hot drinks.
Colours: why Owala names matter
Part of Owala's appeal is its colour drops. Rather than "blue" or "pink", colourways have names such as Beach House, Denim, Daybreak, Shy Marshmallow and Very, Very Dark, and new ones appear regularly. That is why people search for a specific shade – "Owala Beach House" is one of the most common Owala searches that bring UK shoppers to our site. Some colourways and licensed designs (we stock Star Wars, Harry Potter and Disney designs, for example) can be hard to find in the UK, and many of the bottles we carry are international versions, so if you have your heart set on one shade it is worth checking our Owala collection before settling for a near match.
Stanley's palette is softer and more seasonal, with shades such as Rose Quartz, Peony, Coastal Teal, Dried Pine and Lilac across the Quencher and IceFlow ranges. Browse the full Stanley range by size and colour.
Which one should you buy? Our picks by situation
Commuting, school runs and handbags
- Owala FreeSip 710 ml in Beach House – the classic 24 oz size in one of the most searched-for colourways.
- Owala FreeSip Twist 710 ml in Iced Breeze – a slimmer body with a screw-on top and carry loop, for people who prefer a twist lid to a push-button.
Gym, sport and long walks
- Owala FreeSip 946 ml in Daybreak – close to a litre without the full weight of the largest size.
- Owala FreeSip 1.18 L in Denim – the 40 oz size for people who would rather refill once a day.
Car journeys and cup holders
- Owala FreeSip Sway 887 ml in Beach House – the FreeSip lid on a tapered, handled body that slots into cup holders.
- Stanley Quencher H2.0 887 ml in Rose Quartz – the 30 oz Quencher, a manageable size for daily use.
Desk and home
- Stanley Quencher H2.0 1.18 L in Coastal Teal – the full 40 oz tumbler for all-day sipping.
- Stanley IceFlow 2.0 887 ml in Lilac – a flip-straw tumbler that closes when you are not drinking.
- Stanley Quencher ProTour 1.18 L in Dried Pine – a cold-only 40 oz tumbler with a flip straw and textured handle.
Children
- Owala FreeSip Kids 473 ml in Blue Citrus – the same two-way spout in a size that suits a lunch bag.
Already own a Quencher? Spare straws go missing quickly, so a pack of Stanley replacement straws for the 1.18 L Quencher makes a useful stocking filler. You will find other brands and sizes in our sports water bottles collection.
How we chose
We did not run our own lab tests. Instead we compared the manufacturers' published specifications (sizes, lid design, cold-retention claims and cleaning advice) with the details on our own product listings, and we looked at what UK shoppers actually search for when they arrive at Findsworth – size questions such as "40 oz" and colour names such as "Beach House" come up again and again. We then picked one or two models for each everyday situation, favouring lids whose behaviour is clearly described by the maker, and left out models where we could not confirm how the lid seals. Every product linked here was in stock and live on our site when we published.
Quick checklist before you buy
- Convert the size: 24 oz = 710 ml, 30 oz = 887 ml, 32 oz = 946 ml, 40 oz = 1.18 L.
- Decide where it will live: a bag needs a lockable, leak-proof lid (FreeSip); a desk or cup holder suits a handled tumbler (Quencher).
- Check the fit: measure your cup holder if you want a 40 oz size.
- Keep it cold-only unless the listing says hot drinks are fine, and avoid fizzy drinks in straw lids.
- Hand-wash steel bodies where the maker recommends it, and replace worn straws and seals.
- Pick the colour you love – then enjoy free UK delivery and free 30-day returns if it is not quite right.
Frequently asked questions
How many ml is an Owala FreeSip 40 oz?
A 40 oz Owala FreeSip holds about 1.18 litres. One US fluid ounce is roughly 29.6 ml, so the other FreeSip sizes work out at about 710 ml for 24 oz and 946 ml for 32 oz.
Is the Owala FreeSip leak-proof?
Owala describes the FreeSip lid as leak-proof when the push-button lid is closed, and the carry loop folds over the button to lock it. It is designed for cold drinks; Owala advises against hot, carbonated or perishable liquids.
Is the Stanley Quencher leak-proof?
No. Stanley says the Quencher H2.0's straw opening is designed to resist splashes, which is not the same as leak-proof, so it is best kept upright on a desk or in a cup holder. Stanley's flip-straw models such as the IceFlow 2.0 are described as leak-resistant.
Which keeps drinks cold for longer, Owala or Stanley?
Owala claims up to 24 hours cold for the FreeSip. Stanley quotes 11 hours cold and 48 hours with ice for the 1.18 litre Quencher H2.0. Both figures are the makers' own and real results depend on how much ice you use and the room temperature.
Can I put an Owala or Stanley bottle in the dishwasher?
Owala says FreeSip lids are top-rack dishwasher safe but recommends hand-washing the bottle body to protect its finish. Stanley lists the Quencher H2.0 as dishwasher safe. Always check the care notes for your exact model.
Will a 40 oz bottle fit in my car cup holder?
A standard 40 oz FreeSip is tall and wide and may not fit. The Owala FreeSip Sway and Stanley Quencher both have narrower bases designed to slot into most car cup holders, but it is worth measuring yours first.
Which size is best for a child?
The Owala FreeSip Kids 473 ml (16 oz) size is light enough for a school bag and small hands while keeping the same two-way spout as the adult bottle.
