Casual Shirts: What to Buy and What to Pair Them With (A Technical Wardrobe Guide)

Casual shirts are foundational garments in every modern wardrobe, offering flexible functionality across smart-casual, weekend, and transitional wear. Defined by relaxed silhouettes, breathable fabrics, and versatile styling potential, the right casual shirt bridges the gap between structured workwear and leisurewear.

But selecting the right casual shirt isn’t just about aesthetic. To make informed wardrobe choices, you need to understand fabric science, fit logic, seasonal application, and brand-specific sizing. That’s where tellar.co.uk becomes indispensable—offering free size-matching tools across 1,500+ brands based on your exact body measurements or known size in another label.

1. Defining a Casual Shirt: Characteristics and Construction

A casual shirt typically features:

• Non-fused collars (softer, less structured)

• Single or no plackets for relaxed drape

• Rounded hems allowing untucked styling

• Button cuffs, often single-button or roll-tab

• Less rigid interlining in cuffs and yoke

Common Constructions:

Functionally, casual shirts allow increased airflow, freedom of motion, and easier wash-care properties compared to formal shirts. They are built for versatility—ideal for layering or standalone wear across varied temperatures and settings.

2. Understanding Fabric Types and Seasonal Suitability

Each fabric used in casual shirts delivers distinct functional benefits. Below is a breakdown of key fabrics with pros, cons, and seasonal pairing guidance.

Note: If you’re unsure what fabric fits your lifestyle best, read our Shirt Fabric Guide for pros, cons, and care tips.

3. Fit and Cut: Precision Matters

The fit of a casual shirt directly impacts its wearability, silhouette, and comfort.

• Regular Fit: Looser at the chest, waist, and armhole. Suitable for layering.

• Slim Fit: Slight taper at the waist. Ideal for lean or athletic frames.

• Boxy/Oversized Fit: Cut straight, dropped shoulders. Works best on taller or broader individuals.

• Relaxed Fit: Slightly looser than regular, often with pleats or darts to maintain shape.

To eliminate sizing guesswork, tellar.co.uk compares your largest measurement (chest, waist, or hips) against real-world brand data to recommend the exact size—preventing gaping, tightness, or excessive volume.

4. Recommended Styles: Purpose-Driven Selection

Different shirt styles cater to different use cases. Below are the most functional and investment-worthy types of casual shirts, plus pairing tips:

Oxford Shirt

• Use Case: Office casual, travel, dinner dates

• Pair With: Slim chinos, loafers, minimal trainers

• Best Brands:

  • High street:Uniqlo, Arket, M&S Autograph

  • Designer:Sunspel, A.P.C., Reiss

Linen Shirt

• Use Case: Hot weather, layering, holiday wear

• Pair With: Tailored shorts, white jeans, espadrilles

• Best Brands:

  • High street:Mango, H&M Premium, COS

  • Luxury:Theory, Orlebar Brown

Overshirt / Shacket

• Use Case: Autumn/spring layering, casual outerwear

• Pair With: White T-shirt, joggers or raw denim, boots

• Best Brands:

  • Affordable:Weekday, Zara, Bershka

  • Premium:Rag & Bone, Norse Projects, Barbour

Flannel Shirt

• Use Case: Colder months, outdoor casual

• Pair With: Dark jeans, gilets, shearling jackets

• Best Brands:

  • High street:FatFace, Next, Jack Wills

  • Designer:Filson, Patagonia, Saint Laurent

Denim Shirt

• Use Case: Transitional layering, weekend wear

• Pair With: Black chinos, over turtlenecks

• Best Brands:

  • Accessible:Levi’s, Pull & Bear

  • Premium:Diesel, RRL by Ralph Lauren

5. What to Pair Casual Shirts With: Practical Combinations

For more real-time styling inspiration, check our blog:

➡️ Best Shirts for Workwear – What Brands to Buy and How to Wear Them

6. Choosing the Right Shirt for Your Body Shape

Your body type will affect the shirt’s silhouette, shoulder alignment, and overall aesthetic. Tellar’s size-matching tool adjusts based on your unique profile, but here’s a general breakdown:

Read our full fit guide: Shirts – What Style Suits My Body Shape?

7. Shirt Longevity and Care

Extend the life of your shirts with proper care:

• Wash at 30°C to prevent shrinkage and preserve fibres

• Avoid tumble drying linen and flannel to retain shape

• Use a steamer for delicate cottons and blended fabrics

• Button all closures before washing to avoid distortion

• Iron inside-out to preserve surface quality and print

See our expert tips: How to Care for Shirt Materials

Conclusion: Invest with Insight

Casual shirts are no longer generic basics—they're the backbone of modern smart-casual wardrobes. With advances in textile performance, sizing technology, and brand variety, you can now choose shirts tailored to your lifestyle, climate, and body shape.

To remove guesswork, use tellar.co.uk to:

✅ Match your measurements to exact sizes across 1,500+ brands

✅ Build a wardrobe that fits, flatters, and lasts

✅ Switch between CM/inches for precise comparison

✅ Track and update your profile securely for future use

Next Steps – Try It Free

🟢 Create your free size profile now

🟢 Use the size lookup tool for any store

🟢 Explore more shirt styling advice

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Tellar.co.uk – Find your size in 1,500+ brands real-time. It’s free & easy.