CSSBuy Size Guide — How to Measure and Compare Rep Sizing in 2026

CSSBuy Size Guide — How to Measure and Compare Rep Sizing in 2026

Sizing is the number one cause of returns and disappointment in the rep market. The CSSBuy spreadsheet helps by listing factory measurements, but those measurements are only useful if you know how to compare them to your own body. This guide walks you through the complete process of measuring, comparing, and ordering the right size through CSSBuy.

Why Sizing Is Tricky

Rep factories do not follow a universal sizing standard. A Large from one factory may fit like a Medium from another. The CSSBuy spreadsheet addresses this by listing flat-lay measurements for most items, but buyers still need to know how to use those numbers. The most common mistake is assuming that your usual size will match the factory size tag. It usually does not.

The second most common mistake is measuring only the most obvious dimension. For shoes, buyers measure foot length but ignore width. For pants, buyers measure waist but ignore inseam and thigh. For hoodies, buyers measure chest but ignore shoulder drop and length. The CSSBuy spreadsheet includes all relevant measurements, but you need to know which ones to check.

How to Measure Yourself

Before you open the CSSBuy spreadsheet, take your own measurements. Use a fabric tape measure and measure over the clothing you normally wear. Write these numbers down and keep them accessible.

Body Measurements for Clothing

• **Chest**: Measure around the fullest part of your chest, under your arms.
• **Shoulder Width**: Measure from the tip of one shoulder to the other across your back.
• **Sleeve Length**: Measure from the shoulder tip to your wrist.
• **Length**: Measure from the highest point of your shoulder to your desired hem.
• **Waist**: Measure around your natural waistline.
• **Inseam**: Measure from your crotch to your ankle.
• **Thigh**: Measure around the fullest part of your thigh.
• **Hip**: Measure around the fullest part of your hips.

Foot Measurements for Shoes

• **Foot Length**: Trace your foot on paper and measure the longest point.
• **Foot Width**: Measure the widest part of your traced foot.
• **Insole Length**: Measure the insole of your best-fitting shoe.
• **Arch Type**: Note whether you have a flat, normal, or high arch.

How to Read the CSSBuy Spreadsheet Size Chart

The CSSBuy spreadsheet lists size charts in the column next to each item. These charts are factory-specific and may vary between batches. Here is how to read them correctly.

Understanding Flat-Lay Measurements

Most size charts in the CSSBuy spreadsheet use flat-lay measurements. This means the garment is laid flat on a table and measured. A flat-lay chest measurement of 60cm means the full chest circumference is 120cm. Always multiply flat-lay measurements by two to get the full circumference.

Accounting for Stretch and Shrinkage

Some fabrics stretch. The CSSBuy spreadsheet notes stretch percentage for items that include elastane or spandex. A 2% stretch means the measurement can expand by 2% when worn. Shrinkage is harder to predict. Cotton items may shrink 3% to 5% after the first wash.

Comparing to Your Own Measurements

Once you have your body measurements and the factory chart, compare them directly. For fitted items, the factory measurement should be 2cm to 4cm larger than your body measurement. For oversized items, the factory measurement may be 8cm to 15cm larger. The CSSBuy spreadsheet notes whether an item is fitted, regular, or oversized.

Category-Specific Sizing Tips

Shoes

Most rep shoes run slightly small. The CSSBuy spreadsheet notes size deviations for each factory. If the note says "size up 0.5," order half a size larger than your usual. If the note says "size up 1.0," order a full size larger. Always compare insole length to your own insole measurement.

Hoodies and Sweaters

Hoodies are oversized by design. Check the shoulder drop and length measurements. A drop-shoulder hoodie will add 2cm to 4cm to the effective length. The CSSBuy spreadsheet notes hoodie fit types: standard, oversized, and boxy.

T-Shirts

Boxy fits are measured by chest width and shoulder drop. Standard fits are closer to true-to-size. The CSSBuy spreadsheet notes which blanks are used for each item. Trusted blanks like those from major manufacturers are more consistent.

Pants

Pants require the most measurements. You need waist, inseam, thigh, knee, and leg opening. If you are between sizes, choose the larger size and plan for minor tailoring. The CSSBuy spreadsheet notes whether a fabric is stretch or rigid.

Jackets

Jackets are oversized by design. Check shoulder width and arm length first. If you plan to layer, add 2cm to your chest measurement. The CSSBuy spreadsheet notes whether a jacket is true-to-size or oversized.

How to Add Sizing Notes to Your CSSBuy Order

When you submit an order through CSSBuy, include sizing notes in the special instructions field. Write your insole length, chest measurement, or preferred fit. CSSBuy will pass these notes to the seller. This reduces the chance of a size mismatch.

Common Sizing Mistakes to Avoid

• Assuming your usual size works across all factories.
• Ignoring the flat-lay measurement format and forgetting to multiply by two.
• Not accounting for shoulder drop in oversized items.
• Forgetting to check inseam for pants.
• Not reading the factory-specific size note in the CSSBuy spreadsheet.

Final Checklist Before Ordering

Sizing mistakes are expensive and frustrating. The CSSBuy spreadsheet provides the data. This guide provides the method. Together, they will help you order the right size every time.