Glass Bottle and Jar Size Guide: ml, cl, and oz Explained

Understanding bottle and jar sizes is one of the first steps in any packaging project. Whether you are launching a skincare serum, a scented candle, a food product, or a fragrance line, choosing the right volume affects everything from product cost and shelf presence to shipping weight and consumer expectations.

Size terminology can be confusing. The UK uses millilitres and centilitres, the US uses fluid ounces (which are different from UK fluid ounces), and different industries have their own conventions. This guide gives you a single reference for conversions, common sizes by industry, neck finishes, and how to choose the right size for your product.

Size Conversion Table

The table below covers the most common glass bottle and jar sizes. Metric (ml/cl) is standard in the UK and Europe. Imperial (fl oz) is used in some legacy contexts and US-export products.

Quick conversion formulas:

• 1 ml = 0.1 cl
• 1 cl = 10 ml
• 1 UK fluid ounce = 28.41 ml
• 1 US fluid ounce = 29.57 ml
• UK and US fluid ounces are not the same — always check which standard your market requires

Common Sizes by Industry

Each industry has established size conventions. Choosing a standard size helps with consumer expectations, shelf placement, closure compatibility, and regulatory compliance.

Essential Oils and Aromatherapy

Small volumes in amber or blue glass: 5 ml, 10 ml, 15 ml, 30 ml, 50 ml, 100 ml. Dropper bottles and euro-dropper inserts are standard. Browse: 5ml | 10ml | 15ml | 30ml

Candles

Measured in centilitres: 9cl (90 ml), 10cl (100 ml), 20cl (200 ml), 30cl (300 ml), 100cl (1000 ml). The 20cl–30cl range is the standard retail size. Browse our candle glass collection, or see the Ultimate Candle Making Guide.

Diffusers

Reed diffuser bottles typically range from 50 ml to 1000 ml, with 100 ml and 200 ml being the most common retail sizes. Browse: 50ml | 100ml | 200ml | 500ml

Skincare

Wide range depending on product type: 10 ml, 15 ml, 30 ml, 50 ml, 100 ml, 120 ml, 180 ml. Small dropper bottles for serums, squat jars for creams, cosmetic bottles for mists. Browse: 10ml | 15ml | 30ml | 50ml | 100ml

Fragrance

Industry-standard sizes: 10 ml (sample), 15 ml (travel), 30 ml (tester), 50 ml (standard), 100 ml (signature). Browse: 10ml | 15ml | 30ml | 50ml | 100ml

Food

Follows regulated fill weights: 100 ml, 110 ml, 130 ml, 180 ml, 190 ml, 250 ml, 500 ml, 1000 ml. Twist-off lids and cork finishes are common. Browse: 100ml | 250ml | 500ml

Medical and Pharmaceutical

Standard pharmaceutical bottles: 100 ml, 125 ml, 150 ml, 200 ml, 1000 ml. Amber glass for light-sensitive formulations. Child-resistant closures often required. Browse: 100ml | 200ml

Neck Finishes by Size

The neck finish determines which closures (caps, pumps, droppers, sprays) will fit your bottle. It is defined by the diameter and thread type.

Important: Always confirm neck finish compatibility before ordering closures separately. The diameter and thread pattern must match exactly, or the closure will not seal properly.

Choosing the Right Size

When selecting a bottle or jar size, consider these practical factors:

• Product volume — Measure your actual fill volume, then allow headspace. Bottles are typically filled to 90–95% of brimful capacity to allow for thermal expansion and closure insertion.
• Market expectations — Consumers expect certain sizes in certain categories. A 10 ml perfume signals a sample; 100 ml signals a flagship product. Match expectations.
• Price positioning — Smaller sizes create accessible entry points. Larger sizes offer better value per ml. Many brands offer two or three sizes of the same product.
• Shipping weight — Glass is heavy. Larger bottles cost more to ship. Factor this into your per-unit economics, especially for e-commerce.
• Shelf presence — Taller bottles stand out on shelves. Wider jars feel more generous. Consider how your chosen size will look alongside competitors.
• Closure compatibility — Your chosen size must have a compatible neck finish for the closure you want. Confirm before ordering.

For volume pricing across all sizes, see our price breaks guide.

Browse by Size

Browse our full range organised by volume:

• 5ml Collection
• 10ml Collection
• 15ml Collection
• 30ml Collection
• 50ml Collection
• 100ml Collection
• 200ml Collection
• 250ml Collection
• 300ml Collection
• 500ml Collection

Frequently Asked Questions

What is the difference between ml and cl?

Millilitres (ml) and centilitres (cl) are both metric volume measurements. 1 cl equals 10 ml. In the UK glass industry, bottles are typically measured in ml while candle glass is often measured in cl.

Are UK and US fluid ounces the same?

No. A UK fluid ounce is 28.41 ml; a US fluid ounce is 29.57 ml. The difference is small per unit but adds up across production runs. If exporting to the US, always use the US measurement.

Does the stated bottle size mean the actual fill volume?

Bottle sizes refer to brimful capacity — the total volume when filled to the very top. Actual fill volume is typically 90–95% of this to allow for headspace. A "100 ml" bottle will hold about 90–95 ml of product in practice.

What is the most popular candle glass size?

The 20cl–30cl range (200–300 ml) is the most common for retail candles. It provides 40–50 hours of burn time, good scent throw, and fits standard shelving. See our Ultimate Candle Making Guide.

Can I order custom sizes?

Custom moulds are possible for very large orders but involve significant tooling costs and lead times. For most projects, standard sizes are far more cost-effective. Contact us to discuss your requirements.

How do I know which neck finish my bottle uses?

Check the product specification or ask your supplier. The neck finish is defined by diameter (mm) and thread type. If you already have a bottle, measure the outer diameter of the neck opening. Common types include DIN 18, 18/415, R3, FEA 15, and twist-off (TO).

Do you offer samples for testing?

Yes. We supply small quantities of most standard sizes for testing fill volumes, closure compatibility, and labelling. Get in touch to arrange samples.

Browse All Glass by Size