Ring Guides

Engagement Ring Carat Size Guide

When planning your engagement, there are myriad elements to consider, each playing a pivotal role in crafting the perfect proposal moment. One of the most significant decisions lies in selecting the carat size of your engagement ring.

Engagement Ring Carat Size Guide

When planning your engagement, there are myriad elements to consider, each playing a pivotal role in crafting the perfect proposal moment. One of the most significant decisions lies in selecting the carat size of your engagement ring. This choice is not just about aesthetics; it influences the budget, complements personal style, and determines the best shape for the ring. Understanding the nuances of carat weight can help ensure that the ring not only looks stunning but also aligns with your vision and financial planning. For a deeper dive into making these crucial decisions, explore our comprehensive guides on setting a budget, choosing the right ring style and selecting the perfect diamond shape. These resources are designed to provide you with the knowledge and confidence needed to make an informed choice about this lasting symbol of your love.

What is an Engagement Ring Carat

In the realm of engagement rings, the term ‘carat’ refers to the weight of the diamond or gemstone, serving as a key indicator of its size. However, it's crucial to note that carat weight doesn't directly translate to visual size but rather the actual weight of the stone. A higher carat weight typically suggests a larger stone, yet the diamond's cut and shape can influence how large the stone appears. Understanding carat size is an integral part of selecting the perfect engagement ring, as it impacts both the ring's appearance and its price. You can gain a fuller understanding of choosing the right diamond by exploring our blog on the 4Cs of Diamonds.

Browse diamond engagement rings by carat-weight

What is the average engagement ring size?

The average diamond carat size for an engagement ring varies significantly across different regions, reflecting cultural preferences, economic factors and personal tastes. In the UK, the average carat size tends to be around 0.6 to 0.8 carats – or more like 1.25ct for Londoners, as discovered by Queensmith’s annual ring trend report. Meanwhile, in Europe, the average is slightly lower, with many opting for subtle elegance in the range of 0.5 to 0.7 carats. In contrast, the USA often sees a higher average carat size, with many engagements featuring diamonds around 1 to 1.2 carats. Age also plays a role in this choice; younger couples might opt for smaller, more affordable stones, prioritising sustainability or financial prudence, while older couples might choose larger carats, reflecting a different stage in life and financial stability.

Recent studies show that the average diamond carat weight is increasing thanks to the affordability of lab diamonds. Lab diamond engagement ring buyers typically opted for larger carat weights compared to natural diamond buyers with nearly 98.3% of diamonds purchased above 2 carat being lab diamonds, according to recent Queensmith sales figures.

Alise | Senior Jewellery Designer

Our in-house jewellery designer's thoughts on carat sizes

We see a wide range of carat sizes chosen by our clients, reflecting the diversity of tastes and budgets that come through our doors. While there's no one 'most popular' size, we've noticed a trend towards the 1.25 carat range or a little higher for lab diamonds, which seems to offer a sweet spot between visibility and value for many couples.’

Natural diamond vs lab diamond carat weight

The recent emergence of lab diamonds has shifted trends within the diamond industry, notably affecting the average size of diamonds purchased. Due to their more affordable pricing, lab diamonds are enabling buyers to opt for larger carat weights than might be feasible with natural diamonds. This shift has had a ripple effect on market demand for smaller diamonds; stones under 0.70 carats are seeing significantly reduced popularity.

This has also impacted the ring setting styles people are choosing. Where halo rings once dominated trends due to their ability to make the ring look altogether larger, the accessibility of heftier carat weights with lab diamonds has led to a preference for cleaner, more streamlined designs such as solitaires and diamond bands. Moreover, as lab diamonds allow couples to maintain budget-friendly ring purchases, there's a growing interest in intricate details like hidden halos, adding a personal touch without stretching finances.

Which engagement ring shape looks biggest?

For many ring buyers, maximising the visual impact of their engagement ring is a key consideration, with the goal of selecting a shape that appears the largest and most eye-catching. This is where the cut and shape of the diamond come into play, as certain designs can make the stone look bigger than its actual carat weight.

The Marquise cut, with its elongated shape and pointed ends, maximises the stone's surface area, making it appear larger on the finger. Similarly, the Oval cut offers an extended shape that enhances size perception while also flattering the finger with its elegant silhouette. Another shape that tends to look larger is the Pear cut, which combines the qualities of both round and marquise cuts to give an illusion of greater size.

We’re here to help

We get it, you’ve never done this before.

That’s why we have diamond and design experts on hand, who are here to guide you through every step - from understanding what carat, color, cut and clarity mean, to designing the perfect ring.

How many carats should an engagement ring be?

The 'best' carat weight for an engagement ring is deeply personal and varies according to individual preference, lifestyle, and budget. Typically, a carat range of 0.50ct to 1.50ct is popular for its balance between size, quality, and affordability. At Queensmith, such rings can range from £1,500 to over £10,000, reflecting the wide variety of options available within this carat range. The final price is influenced by factors beyond carat weight, including the diamond's cut, clarity, and colour.

What engagement ring carat size is right for my hand?

In the UK, the average size of an engagement ring diamond ranges between 0.6 to 0.8 carats. This size is often chosen for its balance between presence and practicality, suitable for a variety of hand sizes and lifestyles.

Below is a simplified table to give you an idea of how different carat weights translate to diamond diameters, which can help visualise how the stone might look on the hand. Keep in mind, the setting and band width also play significant roles in how the ring ultimately looks and feels when worn.

Carat Weight Approx. Diameter (mm)
0.5 Carat 5.1mm
0.75 Carat 5.9mm
1 Carat 6.5mm
1.5 Carats 7.4mm
2 Carats 8.2mm
Graphic diagram showing different diamond carat weights on a hand. There are six diamonds ranging from 0.50ct to 3.00ct

How to change your engagement ring’s carat size?

Enhancing your engagement ring's appearance without physically changing the diamond's carat size is possible through several creative approaches. One popular method is adding multiple diamonds, such as with stackable bands or a halo setting, to increase the overall sparkle and make the central stone appear larger. Another option is upgrading the diamond at a later date, a choice some couples make for anniversaries or significant milestones. This allows for flexibility in budget and preferences over time. Lastly, taking time to consider whether a larger stone aligns with personal style and daily wearability is crucial. These options don't alter the carat size but can significantly impact the ring's visual appeal and significance.

Choosing the perfect carat size with Queensmith

Choosing the right carat weight for your engagement ring is a personal decision that balances aesthetics, lifestyle, and budget. From understanding what a carat is, to considering the average sizes across different regions, and exploring how to enhance the appearance of your ring, we've covered essential aspects to guide you in making an informed choice. Remember, the 'best' carat size is one that reflects your personal taste and the significance of your commitment.


Ready to take the next step? Book an appointment with one of Queensmith's expert jewellers to explore your options in person and find the perfect engagement ring for you. Visit our engagement rings page for more inspiration and to start your journey toward choosing a ring that truly resonates with your love story.

Frequently Asked Questions

Learn More About Engagement Ring Sizes

Engagement Ring Carat Sizes

Is 0.5 carat too small for engagement rings?

No, this can be a perfect choice for many people. It is refined, elegant and very practical for daily wear for most professions.

Is a 0.9 carat diamond ring a good idea?

0.9 carat diamond engagement rings are a great choice. Many couples aim for one full carat, but this can cost considerably more than a 0.9ct engagement ring despite looking on very slightly bigger. In fact, most people can barely tell a 0.90ct and 1ct diamond apart, if at all.

Is it worth getting a 1 carat diamond?

People often find that a 1 carat diamond is the best value for money, as a diamond’s price does not increase in a linear way. For example, a 2 carat diamond won’t be exactly double the price of its 1 carat counterpart. It can increase drastically, so 1 carat can usually meet the majority of budgets while offering a good size. There is also a psychological 'feel good' factor about owning a 1 carat diamond; it feels substantial, sizeable and like a great achievement.

Is 1.5 carat big for an engagement ring?

No! The perfect size and a very popular size. It’s large enough to make a great impact but it isn’t too flashy.

How popular are 3 carat engagement ring?

Only around 5% of people choose a 3ct engagement ring. This figure has increased significantly thanks to lab grown diamonds, which offer a much larger carat weight for the same price. Less than 0.2% of natural diamond engagement rings feature a 3ct diamond.

Comparing Carat Sizes

Can you tell the difference between 0.75ct and 1ct?

Yes, most people can tell the difference between a 0.75 ct and 1 ct diamond ring when comparing them side by side. There is a 0.25 ct difference between them, or that’s around 0.5mm width in a round diamond, which isn’t huge but is noticeable.

Can you tell the difference between a 1 carat and 0.9 carat diamond ring?

The 0.1ct difference between 0.9ct and 1ct is minimal - typically a difference of around 0.2mm in the diamond’s length. For most people, the difference between a 1 carat and a 0.9 carat diamond ring appears minimal and not noticeable.

What’s the difference between a 1 and 1.25 carat diamond?

There is a noticeable difference in size between a 1 carat and 1.25 carat diamond, with 0.25 ct between them. With a typical round diamond, this will measure approximately just 0.4mm, but most people will be able to tell a slight difference between the two diamonds.

Does a 1 carat and 1.5 carat diamond ring look similar?

You will notice a fairly obvious difference between a 1ct and 1.5ct engagement ring; the latter is a whole half carat bigger, and measures around 1mm more in length. This means a 1.5ct engagement ring will cover significantly more of the finger when worn.

What’s the difference between a 2 carat and 1.7 carat diamond ring?

There is a 0.3 ct difference between a 2 carat and 1.7 carat diamond ring. That equates to around a 2.5mm difference in diameter when viewed from above. This isn’t huge but most people could tell the difference between the two.

Can you tell the difference between 1.9 ct and 2 ct?

The difference in size between a 2 ct and 1.9 ct diamond is minimal - most people wouldn’t notice an obvious difference! The prices of diamonds tend to jump at the full carat mark, like 1 ct, 2 ct and 3 ct, meaning you could make great savings by choosing a diamond size that is just shy of a full carat.

Is there an obvious difference between a 3 carat and 3.5 carat diamond ring?

Yes, there is a fairly noticeable difference between a 3 carat and 3.5 carat diamond ring. If you hold the two side by side, you’ll notice a difference of one to two millimetres. This is small, but you’ll probably be able to tell which is the bigger diamond!

Carat Size Costs

How much does a 0.3 carat diamond ring cost?

As the lowest carat weight you can choose for your ring, you’ll find that a 0.3 carat diamond ring is the least expensive of potential diamond sizes, with the total cost starting around £1,250. A great quality 0.3 ct diamond typically costs £550 if it is a loose lab grown diamond, or closer to £750 for a loose natural diamond. The total price of a 0.3 ct diamond ring will have the additional cost of the ring setting itself, starting at £700.

It’s important to choose a diamond with top cut, colour and reasonably good clarity grades to ensure the diamond has an intense sparkle.

You should be aware that diamond prices fluctuate, and this should be used as a guide price accurate at the time of writing.

How much does a 0.6 ct diamond ring cost?

The total price of a 0.6 carat engagement ring is around £1,700. A loose 0.6 ct lab diamond is priced around £1,000, or that’s more like £2,200 for a natural diamond. In addition to this, the cost of the ring setting starts at £700.

You should be aware that diamond prices fluctuate, and this should be used as a guide price accurate at the time of writing.

How much does a 0.75 ct diamond ring cost?

The total price of a 0.75 carat diamond ring starts at £1,900 for a simple solitaire.

A 0.75 ct loose lab diamond will cost around £1,200, or closer to £3,000 for a loose natural diamond. The ring setting itself will then start at £700, depending on the complexity of the design.

You should be aware that diamond prices fluctuate, and this should be used as a guide price accurate at the time of writing.

How much does a 0.8 carat diamond ring cost?

A great quality 0.8 carat diamond ring will start at £2,000 in total.

The price of a 0.8 ct loose lab grown diamond is around £1,300, or closer to £3,500 for a natural diamond. In addition to this, the price of the ring setting itself will start at £700 for something simple.

You should be aware that diamond prices fluctuate, and this should be used as a guide price accurate at the time of writing.

How much does a 1 carat engagement ring cost?

1 ct engagement rings start at around £2,330 if you choose a simple solitaire setting and a lab diamond. The price varies hugely depending on whether you choose a lab diamond or natural diamond.

A good quality 1 carat diamond typically costs £1,480 if it’s a loose lab grown diamond, or £6,200 if it's a loose natural diamond. The total price of a 1 carat diamond ring will have the additional cost of the ring setting itself, starting at £850.

You should be aware that diamond prices fluctuate, and this should be used as a guide price accurate at the time of writing.

How much does a 1.25 carat diamond engagement ring cost?

The cost of a 1.25 carat engagement ring starts at around £2,700, but prices will vary depending on whether you choose a natural or lab diamond, the quality of the diamond you choose, and the complexity of your preferred ring design.

A loose 1.25 carat natural diamond will start at around £11,000 - whereas a loose 1.25 carat lab grown diamond will be a little over £2,000. In addition to this, you’ll pay a fee for the ring setting itself, starting at £700 for a simple solitaire ring.

You should be aware that diamond prices fluctuate, and this should be used as a guide price accurate at the time of writing.

How much does a 1.5 carat diamond ring cost?

1.5 ct engagement rings start at around £3,725 - but the price varies hugely depending on whether you choose a lab diamond or natural diamond.

A good quality 1.5 carat diamond typically costs £3,025 if it’s a loose lab grown diamond, or upwards of £16,000 if it's a loose natural diamond. Natural diamonds vary much more with high carat weights like 1.5ct, so this could be up to £20,000 or more. The total price of a 1.5 carat diamond ring will have the additional cost of the ring setting itself, starting at £700.

You should be aware that diamond prices fluctuate, and this should be used as a guide price accurate at the time of writing.

How much does a 1.7 ct ring cost?

A 1.7 carat engagement ring could cost upwards of £30,000 for a natural diamond - however, the cost is much lower at around £3,700 for a lab diamond ring. The price will vary depending on the ring style you prefer, with simple solitaire ring designs starting at £700, and the rest of your budget can then be dedicated to finding the perfect diamond.

How much does a 2 carat engagement ring cost?

A 2 carat diamond ring start at around £4,905 - but the price varies hugely depending on whether you choose a lab diamond or natural diamond.

A good quality 2 carat diamond typically costs £4,205 if it’s a loose lab grown diamond, or upwards of £30,000 if it's a loose natural diamond. The total price of a 2 carat diamond ring will have the additional cost of the ring setting itself, starting at £700.

You should be aware that diamond prices fluctuate, and this should be used as a guide price accurate at the time of writing.

How much is a 2.5 carat engagement ring?

A 2.5 carat diamond ring starts at around £8,800 - but the price varies hugely depending on whether you choose a lab diamond or natural diamond.

A good quality 2.5 carat diamond typically costs £8,100 if it’s a loose lab grown diamond, or upwards of £30,000 if it's a loose natural diamond. The total price of a 2.5 carat diamond ring will have the additional cost of the ring setting itself, starting at £700.

You should be aware that diamond prices fluctuate, and this should be used as a guide price accurate at the time of writing.

How much does a 3 carat diamond ring cost?

A 3 carat diamond ring starts at around £9,700 - but the price varies massively depending on whether you choose a lab diamond or natural diamond.

A good quality 3 carat diamond typically costs £9,000 if it’s a loose lab grown diamond, or upwards of £150,000 if it's a loose natural diamond. The total price of a 3 carat diamond ring will have the additional cost of the ring setting itself, starting at £700.

You should be aware that diamond prices fluctuate, and this should be used as a guide price accurate at the time of writing.

Other Questions

What is the most popular diamond shape for an engagement ring?

Round, oval and then emerald cut. Read our latest engagement ring trends report for more popularity details.

How can I choose the best 1 carat engagement ring?

The most important characteristic for a dazzling round 1ct diamond is an ‘Excellent’ (GIA) or ‘Ideal’ (IGI) cut grade - which ensures intense sparkle. Other diamond shapes don’t receive a cut grade, but you should ensure equally great polish and symmetry grades. Next, consider D to F colour diamonds, which will appear bright and colourless. Then, look between VVS1 and SI2 for a clarity grade that doesn’t break the bank, and for diamond that looks clear to the naked eye.

Don’t be afraid to look slightly under 1ct - you could make significant savings with a 0.97ct, 0.98ct or 0.99ct diamond, but they’ll look incredibly similar. In fact, you probably couldn’t tell they’re smaller than 1ct. These are known as ‘underweight’ diamonds and are very rare, so don’t pin too much hope on finding one!

If you’re concerned your budget won’t stretch to a 1 ct diamond ring, consider a lab diamond - which typically cost 60% to 80% less than natural diamonds.

What does a round engagement ring mean?

Round diamonds represent eternal, undying love. The circular shape of a round diamond symbolises something with no beginning or end, that will last forever. You can trust a round diamond engagement ring to never go out of style, and the iconic, timeless diamond shape will forever emit an intense sparkle. Therefore a round diamond ring symbolises reliability, loyalty, enduring passion and a classic kind of love.

What is a natural diamond?

Natural diamonds are formed over billions of years within the Earth’s mantle from high pressure carbon, creating a beautiful, sparkly gemstone.

How much are lab grown diamonds?

Like natural diamonds, man made diamond prices vary depending on quality and size. We offer lab made diamonds starting from around £600 and ranging to upwards of £8000 so there are options to suit all budgets. Browse our loose lab grown diamonds here.

How far in advance do you need to order an engagement ring?

For fast delivery engagement rings, you need to place an order at least two weeks in advance. If your chosen ring includes an intricate setting or diamond cut, make sure you order your engagement ring at least 4 weeks in advance, or longer to be on the safe side. When choosing your design, speak to your jeweller about expected timeframes.

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