Hydro Flask Sizes: Every Bottle in Ounces and Millilitres
Hydro Flask sells bottles from 12 oz to 64 oz in two mouth types, plus lightweight, travel, kids and micro lines. Here is every size in ounces and millilitres, which caps fit which bottles, and how real bottles of the same capacity measure up.
By Feng, Head of After-Sales Service & Online Marketing Lead
Hydro Flask's main water bottles come in two mouth types. Standard Mouth bottles come in 21 oz and 24 oz. Wide Mouth bottles come in 16, 20, 24, 32, 40 and 64 oz. Hydro Flask also lists Lightweight bottles in 16, 24, 32 and 40 oz, Travel bottles in 24, 32 and 40 oz, Kids bottles in 12 and 18 oz, and Micro Hydro bottles in 200, 300 and 400 ml. In millilitres, the main sizes convert to about 621 ml (21 oz), 710 ml (24 oz), 946 ml (32 oz) and 1,183 ml (40 oz). Caps only fit their own mouth type. BG Drinkware, a drinkware manufacturer in Yongkang, China, which is not affiliated with Hydro Flask, makes its own bottles in similar capacities, from 350 ml to 2,000 ml, and lists their real dimensions below.
What sizes do Hydro Flask bottles come in?
From 12 oz to 64 oz, split into lines. The core range is Standard Mouth (21 and 24 oz) and Wide Mouth (16 to 64 oz). Lightweight, Travel and Kids bottles use Wide Mouth caps, and the Micro Hydro line is sized in millilitres. This table lists every size on Hydro Flask's fit chart.
| Line | Sizes | In millilitres | Caps |
|---|---|---|---|
| Standard Mouth | 21, 24 oz | 621, 710 ml | Standard Mouth caps |
| Wide Mouth | 16, 20, 24, 32, 40, 64 oz | 473, 591, 710, 946, 1,183, 1,893 ml | Wide Mouth caps |
| Lightweight | 16, 24, 32, 40 oz | 473, 710, 946, 1,183 ml | Wide Mouth caps |
| Travel | 24, 32, 40 oz | 710, 946, 1,183 ml | Wide Mouth caps |
| Kids | 12, 18 oz | 355, 532 ml | Wide Mouth caps |
| Micro Hydro | — | 200, 300, 400 ml | Not listed |
BG Drinkware is not affiliated with Hydro Flask, and Hydro Flask is a trademark of its owner. Sizes change over time, so check Hydro Flask's own site for the current range. For converting other sizes, see 32 oz water bottle size and 40 oz in litres.
What is the difference between Standard Mouth and Wide Mouth?
The opening, and therefore the cap. A Standard Mouth cap fits only Standard Mouth bottles, and a Wide Mouth cap fits only Wide Mouth bottles. Hydro Flask's fit chart says bottle caps screw on securely, while its tumbler and mug lids have a press-in fit instead.
In BG Drinkware's experience, a narrower mouth is easier to drink from without spilling, and a wider mouth is easier to fill with ice and to clean by hand. The same choice comes up for any bottle range: decide the mouth first, because every cap, straw lid and accessory has to fit it. For lid options, see water bottle lid types.
How big is a bottle of the same capacity, in real dimensions?
Capacity alone does not tell you the height or weight. Two 32 oz bottles can differ by several centimetres, depending on the diameter, the shoulder and the lid. The table below lists dimensions for BG Drinkware bottles at similar capacities, taken from its product pages.
| Near this size | BG Drinkware model | Capacity | Size | Weight |
|---|---|---|---|---|
| 20–21 oz | Bottle with carry strap | 600 ml | 7.5 cm wide, 22.5 cm tall with cap | about 320 g |
| 24 oz | Dual-drink bottle with safety lock | 720 ml | 26.9 cm tall with lid; 70 mm mouth | 390 g with lid |
| 25 oz | Bottle with loop cap | 750 ml | 7.7 × 28.5 cm | about 300 g |
| 32 oz | Dual-drink bottle with safety lock | 940 ml | 27 cm tall with lid; 67 mm mouth | — |
| 32–34 oz | Bottle with loop cap | 1,000 ml | 7.7 × 35.5 cm | about 370 g |
| 64 oz | Outdoor jug with large handle | 1,900 ml | 18.8 × 13.9 × 24 cm with lid | — |
| 64–68 oz | Water jug with spout lid | 2,000 ml | 22.4 cm tall with lid; 9.5 cm mouth | 760 g with lid |
The two 1,000 ml-class bottles show the point: the 940 ml dual-drink bottle is 27 cm tall with its lid, while the 1,000 ml loop-cap bottle is 35.5 cm tall. If height matters, for a cup holder or a bag pocket, ask for the measured dimensions, not just the capacity. See choosing bottle sizes.
Which sizes should a bottle range include?
Most ranges cover three jobs: a small bottle for a bag or a child, a mid-size bottle for the day, and a large one for sport or outdoor use. Hydro Flask's own spread of about 21–24 oz, 32 oz and 40 oz shows the same pattern, with a 64 oz bottle at the top.
When planning your own range, keep the mouth size the same across the sizes where you can, so one set of caps and accessories fits them all. BG Drinkware's standard minimum order is 500 pieces per colour, negotiable, and on some models the minimum is also set per capacity, so ask before splitting an order across many sizes. For large sizes, see the stainless steel water jug guide and outdoor jugs.
What should a brand specify for its own bottle sizes?
Give the capacity in millilitres as well as ounces, the mouth type, the lid, the colour and the logo method. Ask for the measured height, diameter and weight with the lid on, and check the sample against them, because the nominal ounce size can be rounded.
BG Drinkware's standard build is a 304 stainless steel inner wall and a 201 outer wall. A sample of an existing model takes up to 7 days, and bulk production takes 7–12 days after the sample is approved. See water bottles for the full range.
Hydro Flask sizes FAQ
Short answers to the questions people ask most about Hydro Flask sizes, millilitre conversions, cap fit and custom bottles in similar sizes. Hydro Flask details come from its official fit chart; millilitre figures are converted, and BG Drinkware dimensions come from its own product pages.
What are the main Hydro Flask sizes?
The 21 oz and 24 oz Standard Mouth bottles and the 32 oz and 40 oz Wide Mouth bottles are listed on Hydro Flask's fit chart. In millilitres, those are about 621, 710, 946 and 1,183 ml. Check Hydro Flask's own site for the current range.
How many millilitres is a 32 oz Hydro Flask?
About 946 ml, using 29.57 ml per US fluid ounce. A 40 oz bottle is about 1,183 ml and a 64 oz bottle about 1,893 ml. Bottles are usually sold by nominal capacity, so the brimful volume can differ slightly from the label.
Do Standard Mouth and Wide Mouth caps fit each other?
No. Hydro Flask's fit chart says Standard Mouth caps fit Standard Mouth bottles and Wide Mouth caps fit Wide Mouth bottles. Lightweight, Travel and Kids bottles all take Wide Mouth caps. Tumbler and mug lids are a separate, press-in system.
Can I get a custom bottle in a similar size?
Yes, from a manufacturer that makes bottles in similar capacities under your own brand. BG Drinkware, which is not affiliated with Hydro Flask, makes stainless steel bottles from 350 ml to 2,000 ml, with a standard minimum order of 500 pieces per colour, negotiable.
Sources
Hydro Flask is a trademark of its owner. BG Drinkware is not affiliated with Hydro Flask.
Planning a bottle size range?
Send the capacities, quantity, mouth type, lid, colour, logo method, packaging, payment terms and trade terms for a quotation.
