When choosing a diamond, one of the most important decisions you’ll make is shape and cut style. Two of the most popular and time-tested options are the Round Brilliant Cut and the Princess Cut. Each offers a unique look, cost structure, and set of trade-offs. In this article we’ll explore these two shapes, highlight their differences across key criteria (brilliance, size-per-carat, durability, budget, style, etc.), and walk you through how to decide which one is right for you.

What are these cuts?

Round Brilliant Cut

The Round Brilliant Cut is the most popular and classic diamond shape. It features a circular outline when viewed from above, and it typically has 57 or 58 facets (depending on whether you count the culet) designed to maximize light return and sparkle.
Because the proportioning and facet-arrangement of the round brilliant have been highly developed over time (including by mathematician Marcel Tolkowsky in 1919) it is considered the gold-standard for brilliance.

Princess Cut

The Princess Cut is a more modern style — often described as a “square modified brilliant.” It has a square or sometimes slightly rectangular outline when viewed from above, with pointed corners, and a facet arrangement designed to capture sparkle while preserving more of the rough diamond.
It emerged in the 1960s and 1970s and has become one of the most popular “fancy cuts” (i.e., non-round shapes). 

Key Differences — Side by Side

Here are the major areas of comparison:

1. Brilliance & Sparkle

• The Round Brilliant Cut typically delivers the highest light return and brilliance, thanks to its optimized facet structure. According to one source, round brilliant cuts reflect over 90% of the light that enters them, whereas princess cuts reflect around 70%.
• The Princess Cut still offers excellent sparkle—after all it is a “modified brilliant” style—but it tends to be slightly less brilliant than a top-quality round cut. 
• Because of the round’s symmetry and facet design, it also tends to be more forgiving of minor inclusions and color tints. For example, cuts with more light-performance can mask color and clarity issues.
  Bottom line: If you want maximum fire/sparkle and visual “wow,” the round brilliant cut has the edge.

2. Face-Up Size & Visual Impact

• For the same carat weight, a Princess Cut may appear slightly larger or give a bigger “face up” appearance because square shapes can maximize the visible surface area compared with round ones (depending on proportions). Some sources indicate that a princess-cut may appear larger.
• On the flip side, many round brilliants are cut with ideal proportions that maximize diameter relative to depth; hence, in well‐cut stones the visual size may be comparable.
• Also, due to the square shape of princess cuts, edges/corners may draw attention and shape may appear more modern, whereas round shapes flow more classically and may visually elongate fingers.
  Bottom line: If you want a “big look” for your budget, Princess Cut can offer value; if you care more about sparkle, Round may win.

3. Cost & Value

• One of the largest differences lies in cost. Because Round Brilliant cuts require more rough diamond to be removed (and thus more wastage) and because they are in higher demand, they tend to command a premium price.
• In contrast, Princess Cuts retain more of the rough (with less waste) and therefore can cost less per carat compared to equivalent quality round stones. One figure: princess cuts may be ~33% cheaper than rounds of the same carat/clarity/colour.
• So if budget is a major constraint, a princess cut gives an opportunity to trade shape for cost savings, while still maintaining brilliance.
  Bottom line: For budget-conscious buyers, Princess Cut often offers better value; for those prioritising top sparkle and resale value, Round Brilliant is worth the investment.

4. Durability & Setting Considerations

• The Round Brilliant, with its smooth; continuous outline, has no sharp corners and is typically more durable in everyday wear.
• The Princess Cut has crisp corners which can be more prone to chipping or damage, especially if the setting doesn’t offer corner protection (e.g., bezel or halo).
• Therefore, when selecting a Princess Cut, it’s wise to choose a robust setting and ensure the corners are securely protected.
  Bottom line: If the wearer leads an active lifestyle or prefers a low-maintenance ring, Round may be safer; if you love the square look, just be mindful of the corners and choose a secure setting.
  

5. Style, Trends & Finger Shape Suitability

• Round Brilliants: timeless, classic, universally flattering. Because of their symmetry, they suit most hand shapes and finger lengths, and are unlikely to go out of style.
• Princess Cuts: more modern, edgy, geometric. They bring a distinctive square profile which appeals to those seeking something a bit different but still brilliant. Allows for creative settings (east-west, halo square, etc.).
• Finger shape tip: A Round stone can help elongate shorter fingers; a square Princess may suit longer, slender fingers or hands that can carry the angular look. Some prefer the clean lines of square shapes to match modern jewellery designs. Bottom line: The best shape will reflect your personal style and lifestyle — so visualise on your own hand, in real light.

6. Resale and Market Considerations

• Because Round Brilliants are the “standard” and highly liquid in the diamond market, they tend to retain value more easily and resale may be simpler.
• While Princess Cuts are still very popular (one of the top fancy shapes) they may be marginally less liquid or command slightly lower resale premiums.
• If investment/resale is part of your consideration, a well‐cut Round Brilliant is typically a safer bet.
  

How to Choose Between Them: A Buyer’s Guide

Now that you understand the differences, here’s a practical guide to help you decide which cut fits you best.

Step 1: Prioritise Your Goals

Ask yourself:

• Do I prioritise maximum sparkle and brilliance? → Lean Round Brilliant
• Do I prioritise budget efficiency and want a larger look for less cost? → Lean Princess Cut
• Do I want something classic and timeless or something modern and square?
• Will my choice be worn daily, hard-wearing, or occasionally?
• Is resale value important?
  Write down your top 2-3 priorities. This will help focus your selection rather than shape hunting alone.

Step 2: Establish Your Budget

Set a realistic budget (e.g., US$ / INR) for the centre stone (and perhaps include setting if you’re buying a ring).
Because Princess Cuts often deliver better “value per carat,” you may get a larger carat weight or higher clarity for the same budget compared to a Round Brilliant.
However — don’t compromise cut quality just to chase shape or size.

Step 3: Focus on Cut Quality and Certification

• For Round Brilliants: The “Cut” grade is extremely important. Institutes like Gemological Institute of America (GIA) give cut grades (Excellent, Very Good etc). A high-quality cut should be a priority.
• For Princess Cuts: While they may not always be graded using the same exact cut grade as rounds, you still want excellent polish, symmetry, good proportions, and a grading certificate. Low-quality cut even in strong shape will diminish sparkle considerably.
  As one expert put it: “When comparing a princess cut diamond to a round cut diamond … it is a good idea to make no sacrifices in cut quality.”
  Bottom line — poor cut defeats even a high carat or high clarity stone.

Step 4: Compare Same Carat, Colour & Clarity Across Shapes

When you compare a Round vs Princess for the “same” carat weight, make sure you’re comparing equivalent clarity and colour grades. Then evaluate:

• How does each appear in person (visit jeweller if you can)?
• Which one appears larger face-up?
• How does the sparkle/faceting look in natural light and indoor light?
• How does the shape complement your hand/finger?
  Remember: a 1.00 ct round may appear slightly smaller or different in diameter compared to a 1.00 ct princess depending on proportions and how much weight is ‘hidden’ in the pavilion. Some sources say princess cuts may have slightly “shallower” aspects and appear larger for weight.

Step 5: Consider Setting & Lifestyle

• For a Princess Cut: Because of the sharp corners, pick a setting that protects them (e.g., halo, bezel, V-prongs, corner prongs).
• For a Round Brilliant: Many setting styles will look great; it integrates well with different design types.
• Think about wearing frequency: Are you active with hands? Do you wear gloves or do heavy work? If yes — durability and setting protection become more important.
• Also consider maintenance and cleaning: Square shapes may show scratches or wear on corners more. Beware of catching corners on clothing.

Step 6: Visualise & Try In Person

Shape preference is also emotional and personal. Which one you love matters a lot. If possible:

• View both shape options in the price/size/clarity you’re considering.
• See how each catches light in different settings and environments (office light vs sunlight vs candlelight).
• Take a photo of yourself wearing each shape (if possible) to see how it looks on your hand from different angles.
• Think long-term: Will you still love this shape in 10–20 years? Trends matter less than your timeless preference.

Pros & Cons Quick Table

Real-Life Considerations & Common Myths

• Myth:
  “Princess cuts are just as sparkly as rounds.”
   Reality: While princess cuts sparkle extremely well, most gemologist sources still favour the round brilliant in terms of light return.
• Myth:
  “Same carat weight means visually equal size across shapes.”
   Reality: Not always. Due to differing proportions and depths, face-up size can vary. Some shapes use more of the carat weight in depth rather than width/diameter. For example, some princess cuts may carry more weight in depth, making them appear slightly smaller than a round of equivalent carat.
  
  

• Consider lighting and setting effects:
  A well-cut diamond poorly set will underperform. For princess cuts especially, setting impacts how the square corners are presented and protected.

• Resale or upgrade path:
  If you may want to upgrade later, consider that round brilliants are more standard and easier to match/integrate with future pieces or trade-in programs.

• Finger and ring styling:
  Your choice should harmonise with ring setting and your personal style. Even a budget‐friendly shape that you love beats a “top cut” that you don’t.

Final Recommendation: Which One Should You Pick?

Here’s a summary to help you choose:

• If you’re seeking maximum sparkle, have a budget that can accommodate a premium, want something timeless, and want maximum resale or investment potential → go for a Round Brilliant.
  

• If you’re on a budget but still want a beautiful diamond, love modern/square shapes, want to maximise carat size for the money, and are comfortable choosing a protective setting → go for a Princess Cut.
  

Regardless of the shape, remember the critical mantra: cut quality matters most. A poorly cut stone of any shape will disappoint. Always insist on a reputable certificate (e.g., GIA or equivalent), examine the diamond in real light if possible, and evaluate the 4Cs in context of your shape choice.

Conclusion

Choosing between a Round Brilliant and a Princess Cut comes down to balancing style, budget, sparkle, and durability. There’s no universally “better” shape — only the one that aligns with your priorities and ensures you get the most value and aesthetic satisfaction.

When you make your choice with both head and heart, you’ll end up with a diamond that delights you every time you glance at it.

Next steps for you: Visit c6diamonds.co (or your preferred jeweller) and ask to compare actual diamonds in both shapes — similar carat, colour & clarity — under consistent lighting. See how they appear on your hand. Then review cost differences and make your decision.