side-stone engagement ring - what carat diamond should I choose FIside-stone engagement ring - what carat diamond should I choose FI

What Carat Diamond Should I Choose?

Your budget, style, and expectations will impact the size diamond you choose for your jewelry. Read our guide to see what carat diamond works best for you.

11 Minute Read

HomeDiamond AdviceThe 4 Cs of Diamonds - CaratsWhat Carat Diamond Should I Choose?

IGS may receive customer referral fees from the companies listed in this page.

When picking out jewelry, one of your biggest decisions is what carat diamond to purchase. This requires balancing your budget, style, and expectations carefully. In this guide, we'll discuss how carat impacts diamond sizes and budgets for engagement rings, earrings, and pendants. We'll also discuss alternatives for smaller budgets and savvy savers.
Can you tell how large is the center stone in this engagement ring, or if it's over or under one carat? Find the answer below. © CustomMade. Used with permission.
Find this Ring
at CustomMade

What Carat Diamond Should I Get for an Engagement Ring?

For an engagement ring, expectations about carat weight are often at odds with the reality of diamond prices. Consider your options carefully and remember that even rings with small diamonds can be elegant and sparkly. Furthermore, telling the difference between small changes in weight can be difficult. For example, the diamond in the photo above is large, 1.50 cts, but certain engagement ring settings can make smaller stones look even larger than this one.

Keep in mind that the ring setting itself will cost some money. At a minimum, a simple solitaire would usually run around $250. A pavé band or halo setting will bring that cost to about $1,000, while three-stone settings start at around $1,500. More intricate designs and additional accent diamonds and gemstones increase the price of the setting, so it's best to pick an engagement ring setting before finding your diamond.

If you're not sure what you're looking for, check out James Allen's inspiration gallery to see what others have done with a similar budget.

In addition, consider different diamond shapes. Though not quite as popular or sparkly as the traditional round, fancy shapes are becoming more popular, and most diamond cuts are still very sparkly. Better yet, fancy shapes can be 20-40% cheaper than rounds at the same carat weight.

A Note About Carats

Keep in mind that carats measure a diamond's weight, not its dimensions or size. However, you can get an idea of the size of a round diamond by its carat weight. You can also find estimates of sizes for diamonds of different carat weight cut to other popular shapes here.

Video diamond size engagement ring comparison on hand by ZCOVA.

0.10-0.40 Carats

For a diamond budget under $1,000, you'll probably look at diamonds under 0.50 cts. Although round diamonds in this range are under 5 mm across, they can still be incredibly sparkly. Choosing low clarity and color grades will let you find the largest diamond you can, and, at this weight and size, clarity and color have little impact on beauty.

Very small diamonds of 0.10 cts make for beautiful, simple, and understated rings. For a minimalist style, this might be all you're looking for.

Slightly larger diamonds make an elegant choice for an engagement ring.

The petite 1.5mm band makes this 0.34ct diamond stand out. © James Allen. Used with permission.
Find this Ring
at James Allen

0.50 Carats

Half-carat diamonds are a popular choice for engagement rings. With a diamond budget of about $1,000, you can find a half-carat round with great performance. At this weight, a solitaire will stand out, though halo settings are still great for additional sparkle.

A halo setting makes this 0.50ct center stone look larger. © James Allen. Used with permission.
Find this Ring
at James Allen

0.70 Carats

A sweet spot in the compromise between size and price, diamonds around the 0.70-ct mark make great engagement ring stones. A diamond budget of about $2,000 can get you a fine diamond at this weight.

A band that tapers near the center stone will also make your diamond appear larger. © James Allen. Used with permission.
Find this Ring
at James Allen

0.90 Carats

Almost one carat, 0.90 cts is a popular choice for those looking to save on a one-carat diamond. Unless someone's measuring your diamond, they'll never know that it's below 1.00 ct, and the jump in pricing at the one-carat mark makes this diamond weight appealing to those looking for savings. However, since many consumers are opting for 0.90 cts, this has actually caused a small bump in price for diamonds in this range. Expect to spend around $3,000 to $4,000 for a well-cut round 0.90-ct diamond.

A simple solitaire is a beautiful, classic look for a diamond this size. © CustomMade. Used with permission.
Find this Ring
at CustomMade

1.00 Carat

Because it's the most popular weight, diamonds experience a price jump at 1.00 ct. The price jump is especially high for round diamonds, and, at this weight, you'll get the most savings by choosing a fancy shape. With a budget of $4,500, you can find a great one-carat diamond. However, if you're willing to compromise on clarity and color, you may be able to find a one-carat diamond at $3,000.

Read more in our one-carat diamond guide.

At one carat, a three-stone ring won't overwhelm the center stone. © James Allen. Used with permission.
Find this Ring
at James Allen

1.25 Carats

Sizes just over one carat are often overlooked. First-time diamond buyers who aim for a one-carat diamond often opt for higher color or clarity grades when they realize they have room in their budget. Why not go for a higher carat? At this weight, a diamond is noticeably larger than one carat and truly stunning. With a diamond budget of about $6,500, you can find a round 1.25-ct diamond with excellent performance. At $4,000, you could get a great diamond with a lower color grade.

The tapered band on this 1.30-ct diamond solitaire makes the stone look even larger. © CustomMade. Used with permission.
Find this Ring
at CustomMade

1.50 Carats

At 1.50 cts, diamonds begin to look very large, and their sparkle will certainly draw attention. Of course, such a diamond comes with a hefty price tag. For a well-cut round in the near-colorless range, a 1.50-ct diamond will run about $9,000. If you're willing to compromise on color, a budget of $5,500 could work.

In contrast to the 1.30-ct diamond's tapered band, the larger metalwork near this 1.50-ct center stone makes it look somewhat smaller. © CustomMade. Used with permission.
Find this Ring
at CustomMade

2.00 Carats

If you're looking for something big and noticeable, 2.00 cts will certainly make a statement. At this weight, a round diamond is a little over 8 mm in diameter (10 mm = 1 cm). However, finding a well-cut diamond of this size becomes difficult. Make sure you know what you're looking for. For a diamond with great sparkle, you'll need a budget of at least $16,000. Compromising on color can give you significant savings, and a budget of $9,000 to $10,000 should get you a beautiful diamond for a colored gold setting.

"Impeccable Symmetry In a 2.54 c Diamond Ring - 16614," video from The Three Graces. Licensed under CC By-ND 3.0.

3.00 Carats

For a truly stunning ring, a 3.00-ct diamond may be just what you need. At this weight, there's no doubt you'll have a big rock. However, a ring like this has a big price, too. For a three-carat diamond with excellent cut and color, you'll want to budget about $35,000. Again, lower color grades will cost you much less, around $23,000.

Three carats makes for a large and stunning solitaire engagement ring. © James Allen. Used with permission.
Find this Ring
at James Allen

5.00 Carats

If only a celebrity-sized diamond will do, then a 5+ carat stone is what you're looking for. At this weight, diamonds are not only eye-catching and large but also rare, and it's even more difficult to find one with great performance. At this size, budget $60,000 to $100,000 for a well-cut diamond.

Read more in our five-carat diamond guide.

At the five-carat mark, any diamond will have tons of sparkle. © James Allen. Used with permission.
Find this Ring
at James Allen
carat sizes shown on hand
Diamond carat sizes shown on a hand.

What Carat Diamond is Best for Studs?

Diamond studs are sold by the total carat weight (ctw). This means that you'll have to divide the weight in half to know the approximate weight of the diamond on each ear.

diamond studs - what carat diamond should I get
Diamond studs come in a wide range of sizes. You can get something similar at CustomMade. "4 Prong Earrings" photo by TVZ Design. Licensed under CC By 2.0.

0.10-0.25 ctw

At this weight, the diamonds will be quite small. This size is great for a child's gift or for those who prefer understated jewelry. At these sizes, gold pre-set earrings with well-cut, sparkly round diamonds will cost about $100 to $400.

0.30-0.50 ctw

Moving up in carat weight, the diamonds become more noticeable but may still seem small. This range is perfect for a first pair of diamond studs. Expect to spend $300 to $800 for studs of this size.

0.75 ctw

At this size, the diamonds are over 4 mm in diameter and really make an impact. However, prices also increase. Expect to spend $1,000 to $2,000 on diamond studs this size.

1.00 ctw

When you reach the 1-ctw mark, each diamond is over 5 mm in diameter, a very nice size for diamond studs. However, this weight will also come with a significant price tag. Pre-made studs with well-cut diamonds can cost anywhere from $1,500 to $4,000.

From this weight on, have a jeweler build your studs from diamonds you choose. The price of these diamonds makes it worthwhile to check their grade report and review video of their performance before buying.

1.50 ctw

At 1.50 ctw, each earring is noticeably large and can have a ton of sparkle. Nearly 6 mm in diameter, these diamonds may look overly large on petite ears but provide the perfect earlobe coverage for larger ears. Again, in this weight range, it's best to build earrings with laboratory-graded diamonds. Expect to spend at least $4,000 on 1.50-ctw diamond studs.

2.00 ctw

At the 2.00-ctw mark, each diamond weighs about 1 ct, making them large and very sparkly. If you're looking at 2.00-ctw diamond studs, make sure your diamonds come with grade reports from reputable laboratories. At this size, well-cut round diamonds will cost at least $7,000.

What Carat Diamond Should I Get for a Pendant?

Choosing the size of a pendant is tricky, since everyone has different preferences and different neck sizes. If you're buying a pendant for yourself, try on different sizes in a store to see what you like. However, if you fall in love with a larger size diamond, you may be able to save money by shopping online.

If you're buying a diamond solitaire pendant as a gift, take a look at other necklaces to get a sense of what carat diamond looks best and also consider if this is a dress-up/dress-down or special occasion gift.

In case you need to familiarize yourself with necklace lengths, names, and terminology, consult this article.

bezel-set diamond necklace - what carat diamond should I choose
Keep the setting style in mind when choosing a pendant. Bezel settings will make the diamond appear somewhat smaller, while a prong setting will let in more light. You can get something similar at CustomMade. "Full Bezel Diamond Pendant" photo by TVZ Design. Licensed under CC By 2.0.

0.05-0.10 carat

Very small diamonds at the base of the throat add a little sparkle and a lot of elegance to any outfit. This weight is great for those who prefer understated or delicate jewelry. With a gold chain, a solitaire diamond in this range could cost from $150 to $500.

0.25 carat

At 0.25 cts, a round diamond measures about 4 mm in diameter, a great size for a noticeable but not showy pendant. For some petite frames, this might be the ideal size for dress-up/dress-down staple jewelry. At this weight, a pendant would cost about $450 to $700.

Hanging on a thin chain, a 1/4 ct diamond solitaire is elegant and chic. © CustomMade. Used with permission.
Find this Ring
at CustomMade

0.50 carat

A half-carat round diamond will be noticeable and perfect for both everyday wear and special occasions. Measuring about 5 mm across, a diamond this size will certainly have plenty of sparkle. With a budget of $1,500, you can find a beautiful half-carat pendant. At this weight, however, you may want to have a jeweler build your pendant and choose the diamond yourself.

0.75 carat

With a diameter of about 5.7 mm, a pendant of this size is sure to catch compliments. Still in the range to either dress up or down, a 0.75-ct diamond pendant will have a lot of sparkle. It may even be too much for some styles. At this weight, choose your own diamond to ensure it has great sparkle. A pendant this size will cost around $2,000.

1.00 carat

For those that need more sparkle, a one-carat diamond pendant might be the best size. At about 6.5 mm across, this might be the upper limit of what you can pair with jeans and a t-shirt. Of course, pricing jumps at this weight. A one-carat diamond pendant would set you back at least $4,000.

1.50 carat and Larger

At larger sizes, diamonds become very sparkly and may be too much for a casual outfit. Still, some enjoy the look of a 1.50-ct diamond pendant for dressy workplaces.

With pendants, there's no limit to how large a diamond you can get. Unlike fingers and ears, the neck lets you wear heavier jewels.

Diamond Alternatives

If you prefer a larger aesthetic than your budget allows, there are alternatives to mined diamonds with the same beauty.

Laboratory-Created Diamonds

These are real diamonds, only they're made in a lab. With the exact same appearance as mined diamonds but a much lower price, these make a great alternative. Check out our lab-created diamond guide.


Synthetic moissanite is another option. With prices even lower than lab-made diamonds, many consumers are opting for moissanite engagement rings. Read more about moissanite vs diamond.

Moissanite provides a great cost savings at any size. © CustomMade. Used with permission.
Find this Ring
at CustomMade

White Sapphire

If you prefer a mined gem to a synthetic alternative, consider white sapphire. Although its appearance differs somewhat from diamond, a well-cut white sapphire can still have great sparkle.

Where Should I Buy Diamond Jewelry?

Regardless of what carat diamond you purchase, make sure to view the diamond before you buy. Diamond value comes primarily from the quality of its cut and how well it performs, so it's essential you see how the diamond sparkles while you're shopping.

If you're buying diamonds online for an engagement ring, pendant, or studs, make sure you can view closeup videos of the diamonds. Both James Allen and Blue Nile have hundreds of thousands of diamonds available, each with a 360° video so you can assess how they perform. They also have options for build-it-yourself engagement rings, studs, and pendants, as well as reliable return policies, making them the top choices for buying online. However, James Allen currently offers many more engagement ring styles.

Alternatively, CustomMade offers design services for custom jewelry, letting you create a completely unique piece suited to your style. With their expert guidance, you'll find the perfect stone for your personality and budget.

Addison Rice

A geologist, environmental engineer and Caltech graduate, Addison’s interest in the mesmerizing and beautiful results of earth’s geological processes began in her elementary school’s environmental club. When she isn’t writing about gems and minerals, Addison spends winters studying ancient climates in Iceland and summers hiking the Colorado Rockies.

Never Stop Learning

When you join the IGS community, you get trusted diamond & gemstone information when you need it.

Become a Member

Get Gemology Insights

Get started with the International Gem Society’s free guide to gemstone identification. Join our weekly newsletter & get a free copy of the Gem ID Checklist!