How much does a 4-carat lab-grown diamond cost?
In our October 26, 2026 price check, a loose 4-carat lab-grown diamond cost $1,117 to $2,256 among the sellers with matching listings. Ritani was $1,117; With Clarity was $2,256. These are sampled prices for closely matched round diamonds, before a setting and tax.
We looked for round diamonds from 3.95 to 4.05 carats, with E color, VVS2 clarity, and a high cut grade. These prices exclude the setting, taxes, and optional protection plan.
Read our Ritani review See four-carat diamonds at Ritani
Four-carat lab-grown diamond prices in 2026
These jewelers had matching round diamonds in our latest inventory check. Compare the same grades before choosing on price. Every diamond was 3.95–4.05 carats, E color, VVS2 clarity and IGI graded. Ritani rounds had its Ideal label; other sellers’ rounds had Ideal or Excellent labels.
| Jeweler | Price | Sample | Browse |
|---|---|---|---|
| Ritani | $1,117 | Middle price of 5 lower-priced matches105 diamonds matched these grades | See at Ritani ↗ |
| With Clarity | $2,256 | Middle price of 5 lower-priced matches74 diamonds matched these grades | See at With Clarity ↗ |
Prices are in US dollars for the loose diamond, before a setting and tax. Each jeweler contributes one result to the seller comparison.
See the September 2026 seller comparison
“Typical” is the middle of the seller benchmark prices above. Each seller counts once, so a jeweler with a much larger inventory cannot pull the figure down simply by listing more diamonds.
| Seller and sample | Price | Difference |
|---|---|---|
| RitaniMiddle price of five lower-priced diamonds | $1,246 | Lowest in our test |
| With Clarity4.00 ct current E/VVS2 Excellent-cut sale price | $3,067 | 146.1% more |
| Grown Brilliance4.01 ct current E/VVS2 Excellent-cut result | $3,605 | 189.3% more |
| Brilliant EarthMiddle price of five lower-priced comparable diamonds; grading lab not provided | $5,700 | 357.5% more |
| Blue Nile4.00 ct current GIA Excellent-cut result | $6,388 | 412.7% more |
The gap is more than $5,000 for broadly similar headline grades. Some buyers will value Blue Nile's showrooms, support, inspection tools, or ring builder. Those services can be worthwhile, but they do not make price comparison any less important.
What does a four-carat diamond look like?
A well-proportioned four-carat round diamond is roughly 10.2 millimeters across. It has a very large face-up presence and will dominate most engagement-ring settings. An oval, pear, marquise, or emerald cut can look even larger because the stone stretches farther along the finger.
At this size, comfort and security matter. A low basket, sturdy prongs, and a band wide enough to balance the stone can make the ring easier to wear. Very thin bands may look elegant in photographs but can spin or feel top-heavy.
Buying a four-carat diamond well
Cut should come before the exact milestone. A large poorly cut diamond can show obvious darkness, weak sparkle, or excess weight hidden in the depth. Compare the video, proportions, and millimeter dimensions—not merely the carat number.
E/VVS2 keeps our price test consistent, but many buyers can save with G–H color and eye-clean VS1–VS2 clarity. Four carats is large enough that tint and inclusions may be easier to spot, so inspect the individual stone carefully. Emerald and Asscher cuts are especially revealing because their broad facets make inclusions more visible.
Search below four carats. A well-cut 3.85- to 3.99-carat diamond can look virtually the same while avoiding a milestone premium. Then compare the complete ring totals and return rules before customizing or engraving.
Four-carat round versus fancy-shaped diamonds
Fancy shapes can offer excellent value. Elongated ovals, pears, marquises, and emerald cuts often look larger than a four-carat round diamond. Some shapes cost less, but the price changes with demand, proportions, and how efficiently each stone was cut.
For our September shape comparison, we used the five lowest qualifying Ritani API results for each of ten shapes. Every diamond was 3.95 to 4.05 carats, E color, VVS2 clarity, and IGI graded. Round diamonds had Ritani's Ideal label; the fancy shapes had Very Good or better cut labels. In total, 2,539 Ritani diamonds met those rules.
We compared 10 shapes at Ritani to keep seller markups out of the comparison. Every diamond was 3.95–4.05 carats, E color, VVS2 clarity and IGI graded. Round diamonds had Ritani’s Ideal label; fancy shapes had Very Good or better labels.
| Shape | Price | Sample |
|---|---|---|
| Radiant | $1,094 | Middle price of 5 lower-priced matches34 diamonds matched these grades |
| Round | $1,117 | Middle price of 5 lower-priced matches105 diamonds matched these grades |
| Oval | $1,196 | Middle price of 5 lower-priced matches53 diamonds matched these grades |
| Emerald | $1,211 | Middle price of 5 lower-priced matches12 diamonds matched these grades |
| Marquise | $1,261 | Middle price of 5 lower-priced matches13 diamonds matched these grades |
| Princess | $1,318 | Middle price of 5 lower-priced matches5 diamonds matched these grades |
| Cushion | $1,320 | Middle price of 5 lower-priced matches18 diamonds matched these grades |
| Asscher | $1,352 | Middle price of 5 lower-priced matches5 diamonds matched these grades |
| Pear | $1,369 | Middle price of 3 lower-priced matches3 diamonds matched these grades |
| Heart | $1,440 | Middle price of 5 lower-priced matches8 diamonds matched these grades |
Prices are in US dollars for the loose diamond, before a setting and tax. Each jeweler contributes one result to the seller comparison.
See the September 2026 shape comparison
| Shape | Middle price | Sample range | Recorded cut label |
|---|---|---|---|
| Round | $1,246 | $1,161–$1,251 | Ideal |
| Oval | $1,259 | $1,249–$1,259 | Very Good |
| Emerald | $1,337 | $1,308–$1,346 | Very Good |
| Pear | $1,171 | $1,171–$1,174 | Very Good |
| Marquise | $1,269 | $1,259–$1,269 | Very Good |
| Radiant | $1,085 | $1,074–$1,085 | Very Good |
| Cushion | $1,362 | $1,349–$1,390 | Very Good |
| Princess | $1,081 | $1,043–$1,087 | Very Good |
| Asscher | $1,531 | $1,374–$1,630 | Very Good |
| Heart | $1,337 | $1,114–$1,384 | Very Good |
In the September comparison, Princess was the least expensive shape, with a middle price of $1,081 among its five lowest qualifying listings. Asscher was highest at $1,531. The spread within one seller is much smaller than the spread between sellers. Shape should therefore be a design choice first, not a prediction about which inventory will always be cheapest.
Current four-carat examples
round · IGI
$1,161
4.00 ct · E · VVS2 · Ideal
Lowest qualifying round result in the API capture.
Visit Ritani
oval · IGI
$1,249
3.96 ct · E · VVS2 · Very Good
Lowest qualifying oval result in the API capture.
Visit Ritani
emerald · IGI
$1,308
4.02 ct · E · VVS2 · Very Good
Lowest qualifying emerald result in the API capture.
Visit Ritani
pear · IGI
$1,171
3.95 ct · E · VVS2 · Very Good
Lowest qualifying pear result in the API capture.
Visit RitaniRitani's catalog images show each diamond shape, not the exact stones in our sample. Listings and prices can change after our check, so confirm the current diamond on the seller's site.
For elongated shapes, look for a pleasing outline and manageable bow tie. For step cuts, check that the center does not go dark or look transparent. At four carats, these details are easy to see from normal distance.
Ring styles that work at four carats
A solitaire is the cleanest way to let a stone this large lead. Hidden halos and small accent diamonds add detail without making the face-up outline much wider. A three-stone setting is possible, but it creates a very broad ring and needs careful proportioning.
Step-cut design from Ritani
Hidden-halo design from Grown Brilliance
The white-metal ring pictured at the top adds small diamonds beneath the center and along the shoulders. It is an option when you want detail without a very wide halo.
Pavé cathedral design from James Allen
We would choose a secure basket and try the ring on before committing if possible. Also check whether resizing, customization, or a special-order setting changes the return policy.
Where should you buy a four-carat diamond?
Prices can vary widely within the same carat range. Compare the actual diamond, grading report and complete ring price—not only the headline price—before choosing a seller.
| Jeweler | Best for | Our rating | Shop |
|---|---|---|---|
| Ritani | Prices, loose-diamond selection and value | 4.7/5 | See at Ritani |
| Blue Nile | A polished all-round shopping experience | 4.6/5 | See at Blue Nile |
| Grown Brilliance | Finished jewelry and distinctive ring designs | 4.5/5 | See at Grown Brilliance |
| Brilliant Earth | Premium settings, showrooms and guided shopping | 4.5/5 | See at Brilliant Earth |
Ritani: best for price
Ritani was dramatically less expensive and offered thousands of qualifying stones. Its filters and cost transparency make it the best place to start.
Blue Nile: best all-round alternative
Blue Nile's benchmark was much higher, but it offers detailed videos, support, showrooms, and a polished ring builder. Its inventory now includes the James Allen collection.
Grown Brilliance: best for distinctive settings
Grown Brilliance is one of our preferred sellers for finished jewelry and design-led engagement rings. We have bought and returned several pieces and found the finish, packaging, and service strong.
Brilliant Earth: best for showrooms and labeled sustainability options
Brilliant Earth is worth comparing if you value its showrooms, ring designs, or Renewable, Capture, and Sustainably Rated lab-diamond collections.
Is a four-carat lab-grown diamond worth it?
It can be, if you want a genuinely large diamond and will enjoy wearing it. A comparable mined diamond can cost far more. The practical compromises are the ring's scale, weaker resale market, and the need to inspect a large stone carefully.
Do not treat it as an investment. Lab-grown prices have fallen and could fall further. Environmental claims also vary by producer, so look for concrete product-level evidence rather than assuming every lab-grown diamond has the same footprint.
How four-carat prices have changed
Our earlier research found round four-carat lab-grown diamond prices from $3,483 to $21,290 across six sellers. It used I–J color and VS1–VS2 clarity and seller price ranges. The current benchmark is narrower and higher grade, so this is historical context rather than a like-for-like index.
September 2026 price comparison
In our September 2026 comparison, a loose four-carat lab-grown diamond cost $1,246 to $6,388. Ritani was the least expensive seller, while Blue Nile had the highest close benchmark. The seller-balanced typical price was $3,605.
In our Ritani catalog check, the middle price among its five lowest qualifying round diamonds was $1,246. We count each seller once so that Ritani's large inventory does not dominate the comparison.
Earlier round-diamond comparison
$3,483–$21,290
6 sellers · Round diamonds near four carats, I–J color, VS1–VS2 clarity, and Excellent or Ideal cut; seller ranges rather than one shared aggregation.
September 2026 test
$1,246–$6,388
5 sellers · Round diamonds from 3.95 to 4.05 carats, E color, VVS2 clarity, and a high cut grade; IGI grading where the source exposed it.
Earlier studies used I–J color and VS1–VS2 clarity. The 2026 comparisons use E color and VVS2 clarity; each table lists its own cut and grading rules.
See our earlier round-diamond price comparison
Round brilliant lab-grown diamonds close to the target weight; Excellent (GIA) or Ideal (IGI) cut, I–J color and VS1–VS2 clarity.
Brilliant Earth and James Allen used higher minimum grades in this comparison.
| Jeweler | Recorded price range |
|---|---|
| Ritani | $3,483–$5,267 |
| Clean Origin | $3,949–$7,044 |
| With Clarity | $4,248–$17,209 |
| Grown Brilliance | $4,340–$6,510 |
| Brilliant Earth | $8,140–$21,290 |
| James Allen | $15,340–$19,460 |
These are prices from our earlier seller comparison, not current offers. The Brilliant Earth range included its seller-labeled sustainable collection. James Allen is now a collection at Blue Nile.
See our earlier fancy-shape comparison
Starting prices near four carats, I–J color, VS1–VS2 clarity, and Very Good or better seller-reported cut.
| Seller | oval | emerald | pear | princess | radiant | cushion | heart |
|---|---|---|---|---|---|---|---|
| Ritani | $3,364 | $2,960 | $3,196 | $3,719 | $3,187 | $3,651 | $5,109 |
| Clean Origin | $3,508 | $2,879 | $4,594 | $2,912 | $2,937 | $2,597 | $7,741 |
| With Clarity | $3,686 | $3,208 | — | $3,295 | $3,405 | $3,305 | — |
| Grown Brilliance | $4,685 | $6,225 | $8,325 | $5,205 | $4,060 | $5,570 | — |
| Brilliant Earth | $7,690 | $8,010 | $6,670 | $7,190 | $8,080 | $7,820 | $10,180 |
| James Allen (historical) | $13,680 | $5,980 | $13,030 | $7,320 | $16,270 | $9,640 | $15,650 |
Our verdict
Close four-carat lab-grown diamonds cost $1,246 to $6,388 in our September 2026 test, with a seller-balanced typical price of $3,605. Ritani is the clear place to start on price. With Clarity offers a useful middle-ground comparison, while Grown Brilliance deserves a look for the setting itself.
How we researched four-carat prices
We checked US listings on September 3, 2026. The target was 3.95–4.05 carats, E color, VVS2 clarity, and a high cut grade. Ritani's complete filtered API capture produced 2,539 qualifying offers across ten shapes. Brilliant Earth's feed supplied 145 close high-cut round results but does not expose the grading lab. With Clarity and Grown Brilliance contributed current E/VVS2 public matches; Blue Nile contributed a current four-carat GIA Excellent-cut result.
The current shape table compares shapes within Ritani, so different seller markups do not distort the result. Each seller contributes one benchmark to the seller-balanced typical price.
These dated tables show the cut labels recorded in that study. Check the current diamond listing when choosing a stone.
To work out a typical price across sellers, we sort their benchmark prices from lowest to highest and take the middle value, or the average of the middle two. Each seller contributes one benchmark, regardless of inventory size.
Ritani's complete filtered API capture produced 2,539 qualifying diamonds across ten shapes. Brilliant Earth's feed supplied 145 close high-cut round results, but no grading-lab field. With Clarity and Grown Brilliance contributed current E/VVS2 public matches. Blue Nile's result was a current close public GIA-graded diamond. We use the middle of the seller benchmark prices to prevent one large, inexpensive feed from distorting the typical price.
The earlier seller and shape tables remain as a separate comparison. Current seller and shape comparisons are separate: one compares places to buy, while the other holds the seller constant.
Compare other carat weights
- 0.5-carat lab-grown diamond prices
- 0.75-carat lab-grown diamond prices
- 1-carat lab-grown diamond prices
- 1.5-carat lab-grown diamond prices
- 2-carat lab-grown diamond prices
- 3-carat lab-grown diamond prices
- 5-carat lab-grown diamond prices
- 6-carat lab-grown diamond prices
Update history
First published in March 2024. The September 2026 update adds new seller and shape comparisons and a large-ring example to help judge visible size. Shopping recommendations now reflect James Allen’s move into Blue Nile.
Questions and experiences
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