Key takeaways

• Size labels vary between brands: compare garment measurements, not labels.
• Collect sizes from wearers; use default ratios only when you cannot ask.
• Pre-shrunk fabric and 30°C washing keep shirts the right size.
• Run fit sessions with real people who move, bend and reach.
• Measurement tolerances (for example ±1–1.5cm on chest) are checked during production.

Introduction

Sizing is where T-shirt orders quietly fail. The design is perfect and the print is sharp, yet half the staff say their shirts are too tight, the boxes are full of unused XXLs and nobody has a medium. Or the shirts fit perfectly on delivery day and are a size smaller after the first wash.

Getting fit and size right is not difficult, but it requires understanding how T-shirt fits differ, how size charts are measured, how sizes are graded, why fabrics shrink and how to plan the size split for a group. This article covers all of these, and ends with care advice that keeps T-shirts fitting and looking good for longer.

Understanding T-shirt fits

“Fit” describes how a T-shirt’s shape relates to the body. The same size label can mean very different garments in different fits.

Classic or regular fit

A straight body, neither tight nor loose, with comfortable room across the chest and upper arms. Teepig describes its classic or original fit as neither too loose nor too tight, and not tight on the upper arms. This is the safest choice for mixed groups, uniforms and events.

Slim or fitted

Cut closer to the body, with narrower sleeves and often a slightly tapered waist. It looks sharp on slimmer wearers but can feel restrictive on others, especially in hot weather.

Women’s or ladies fit

Shaped through the waist, often with shorter, narrower sleeves, a lower or scoop neck and sometimes a slightly longer body. Teepig notes that ladies fits are cut for a shaped look. Many women prefer a unisex fit for workwear, so offer both where possible.

Relaxed and boxy

Wider body and shorter length, giving a square silhouette. Popular in fashion and streetwear, usually in heavier fabrics of 200gsm or more.

Oversized

Dropped shoulders, wide body, longer sleeves and often a longer length. Oversized fits are designed to look big. A customer should usually buy their normal size, not size up.

Unisex

Essentially a classic men’s fit offered to everyone. It simplifies ordering for mixed groups, but smaller women may find the shoulders and length too large.

Children’s and youth

Graded by age or height, often with more generous room for growth. Children’s sizes need their own size chart and are often subject to stricter safety rules on trims, such as drawstrings and small parts.

Fit details beyond the body

• Neckline: crew neck is the standard. V-neck and scoop necks suit some fashion and women’s styles. Neck rib width and how tightly it is set affect comfort and how the collar holds its shape.
• Sleeves: set-in sleeves give a neat shoulder. Drop shoulders give a relaxed, casual look. Raglan sleeves run in a diagonal seam to the collar and suit sportswear.
• Length: body length matters for both looks and practicality, for example staff who bend and reach all day.
• Side seams or tubular: some budget T-shirts are knitted in a tube with no side seams. Side-seamed T-shirts hold their shape better and allow shaped fits.

How a T-shirt size chart works

A T-shirt size chart lists garment measurements, not body measurements. Common points of measure are:

Chest width is often given as a half chest, measured flat. Double it to get the full circumference of the garment.

Comparing with body measurements

To choose a size, compare garment measurements with a shirt that already fits well. Lay that shirt flat, measure its chest width and body length, and find the closest match in the size chart. This is far more reliable than relying on size labels, which vary between brands and countries.

Teepig makes a related point: sizes vary between styles, and some brands tend to run small, so the next size up is often advised. Always check the specific size chart for the specific garment.

Grading: how sizes relate to each other

Grading is the process of creating each size from the base sample size. A grading table states how much each measurement increases between sizes. For example, a typical T-shirt might increase chest width by 5cm and body length by 2cm per size.

Good grading keeps proportions right across the range. Poor grading creates small sizes that are too long or large sizes that are too short and wide. When you approve a size set (one sample in every size), check the smallest and largest sizes carefully, as these are where grading problems appear.

Size ranges

Adult T-shirts commonly run from XS or S to 2XL or 3XL. Teepig offers some styles from XS to 5XL. Larger sizes may cost more because they use more fabric. Uniform programmes should include the full range their staff need, rather than leaving larger staff without suitable shirts.

Planning the size split for bulk orders

Ask, don’t guess

For staff uniforms, teams and clubs, the best size split comes from the wearers themselves. Collect sizes before ordering, ideally after people try on samples in each size.

Default ratios for unknown groups

For events and giveaways where you cannot ask, use a default ratio and adjust it for your audience. An illustrative split for an adult unisex event in Sri Lanka might be:

Adjust for your audience. A university event may need more smalls, while a corporate group of older staff may need more large sizes. If women make up a large share of the audience, consider ordering women’s fits or more S and XS.

Keep spares

For uniforms, order a small buffer of the most common sizes for new starters and replacements. Reordering a few pieces later often costs more per piece than adding them to the original order.

Shrinkage: why shirts get smaller

What causes shrinkage

Knitted cotton fabric is stretched during knitting, dyeing and finishing. When the fabric is washed and dried, especially with heat, the fibres relax and the fabric contracts, mostly in length.

Shrinkage is worst in:

• 100% cotton fabrics that have not been pre-shrunk (compacted).
• Hot washes and tumble drying.
• Loosely knitted, lightweight fabrics.

Teepig notes that semi-fitted, softer styles can shrink if washed hot, and recommends considering one size up for these. It also notes that heavier ringspun shirts are less likely to shrink.

How manufacturers control shrinkage

• Compacting: mechanical pre-shrinking of the fabric before cutting.
• Testing: fabric is washed and measured before cutting, and patterns are adjusted if needed.
• Tolerances: a common target is shrinkage within about 5% in length and width.
• Blends: adding polyester improves dimensional stability.

Twisting (spirality)

A T-shirt whose side seams drift towards the front after washing has a problem called spirality or torque. It comes from the twist in the yarn and how the fabric is knitted and finished. It can also be made worse if panels are cut off-grain.

Prevention is in the factory: balanced yarn, correct finishing and careful cutting. A wash test on the pre-production sample will reveal it.

Care: keeping shirts the right size and colour

Good care extends the life of every T-shirt and its print. Teepig’s care advice is straightforward:

• Wash at 30°C or lower. Cooler washes reduce shrinkage, fading and print wear.
• Avoid tumble drying. Heat is the biggest cause of shrinkage and print cracking.
• Do not iron over the print. Iron inside out, or around the print.

Additional tips:

• Turn shirts inside out before washing, to protect the print and reduce pilling.
• Wash with similar colours, especially for new dark shirts.
• Avoid bleach and strong stain removers on printed areas.
• Dry in shade. In strong Sri Lankan sunlight, drying dark shirts inside out in the shade reduces fading.
• Reshape while damp and dry flat or on a hanger to keep the shape.

Care labels

Care labels tell wearers how to look after the garment, using standard care symbols defined in ISO 3758. In many markets, garments must also show fibre content, and textiles sold in the EU must carry fibre composition labels under the EU Textile Regulation. A correct care label is not just a legal detail. It reduces complaints about shrinkage and fading.

How to run a fit session

For cut-and-sew projects and large uniform programmes, a fit session is the most valuable hour in the whole process. Here is how to run one well.

1. Choose fit models. Use real people whose measurements match your base size, usually a medium. For a uniform, include people who represent the range of body shapes in your workforce.
2. Wear the sample properly. The fit model should wear the shirt as it will be worn, tucked or untucked, and with whatever goes over it, such as an apron, jacket or lanyard.
3. Move. Ask the model to raise their arms, bend, reach forward and sit. A shirt that looks perfect standing still may ride up, pull across the back or gape at the neck when the wearer moves.
4. Check the details. Look at shoulder seam position, sleeve length, neck opening, body length, and how the hem sits.
5. Measure and record. Note every change in centimetres against the measurement chart, with photographs.
6. Revise and re-check. The factory adjusts the pattern and makes a new sample. Repeat until the fit is approved.

Fit comments should be specific. “Feels tight” is hard to act on. “Chest feels tight when reaching forward; add 2cm to the chest width and 1cm to the back” can be put straight into the pattern.

Measurement tolerances

No two garments in a production run are exactly identical. Fabric stretches slightly, and sewing introduces small variations. That is why measurement charts include tolerances: the acceptable range above or below each target measurement.

Typical tolerances for T-shirts are:

During production, inline measurement checks compare garments against these tolerances. Measurements outside tolerance are corrected on the line, before thousands of pieces are affected. Inline measurement is the third of Dsigngo’s five quality gates.

Body measurements for wearers

When collecting sizes from staff or customers, some people will not have a shirt to measure. A simple body measurement guide helps:

• Chest: measure around the fullest part of the chest, under the arms, keeping the tape level.
• Waist: measure around the natural waistline.
• Height: useful for choosing body length, especially for very tall or short wearers.

The garment chest measurement should be larger than the body chest measurement. That difference is called ease. A classic-fit T-shirt might have 10–15cm of ease around the chest, a slim fit less, and an oversized fit much more. Publishing both body and garment measurements helps wearers choose correctly.

Fit for roles and working conditions

Uniform T-shirts and polos need to suit the work as well as the wearer:

• Warehouse and production staff need room across the back and shoulders for lifting and reaching, and a longer body so shirts stay tucked in.
• Hospitality and retail staff need a neat, professional look. A classic or slightly tailored fit in a fabric that resists creasing works well.
• Field and outdoor staff need breathable fabrics and, in Sri Lanka’s heat, a slightly relaxed fit that allows air to move.
• Drivers and delivery staff need shirts that do not ride up when seated.
• Event volunteers need a fit that suits the widest possible range of people, usually a unisex classic fit.

Sizing across markets

Sri Lankan brands that sell abroad, or companies with staff in both Sri Lanka and the UAE, should remember that size labels are not universal. A medium in one market can be a large in another. European, UK, US and Asian brands often use different body standards. When producing for several markets, publish garment measurements for every size, and consider adding chest measurements to the size label itself, for example “M / 96–101cm chest”. This simple step reduces confusion and returns wherever the shirts are worn.

Sizing for online sales

If you sell T-shirts online, sizing is your biggest cause of returns. Reduce them by:

• Publishing a garment size chart with measurements in centimetres and inches.
• Showing how to measure a favourite shirt and compare.
• Stating the model’s height and the size they are wearing in photos.
• Describing the fit in words, for example “relaxed, boxy fit, size down for a closer fit”.
• Collecting feedback from returns and updating the size advice.

An example in practice

The following example is illustrative and does not describe a real client.

A logistics company in Colombo orders polo shirts and T-shirts for 240 warehouse and office staff. Rather than guessing, Dsigngo sends a set of fit samples in S to 3XL to each site for a week. Staff try them on and record their sizes on a shared form. The result shows more 2XL and 3XL than the default ratio would have predicted, and a preference among many women for a unisex rather than a fitted women’s polo. The final order matches actual needs, with a 5% buffer of the three most common sizes held for new joiners.

How Dsigngo Group helps

Dsigngo Group helps clients choose fits, provides size charts and fit samples, and manages size collection for staff and team orders. For cut-and-sew projects, including our own brand, Duiker, we develop and grade patterns to your specification and check every size during sampling and production.

Frequently asked questions

Should I size up in case the shirts shrink?

Not if the fabric is pre-shrunk and you wash at 30°C. For lightweight semi-fitted styles, some brands advise one size up. Check the garment’s guidance.

Why do two medium shirts from different brands fit differently?

Each brand uses its own measurements and fit. Always compare garment measurements, not labels.

Can you make sizes beyond 3XL?

Many styles are available in 4XL and 5XL, and cut-and-sew orders can extend the size range.

How do I measure a T-shirt?

Lay it flat, measure across the chest just below the armholes, and from the highest shoulder point to the hem.

What is an acceptable shrinkage level?

Many specifications allow up to about 5% in length and width after washing. Premium garments aim for less.

Conclusion

Fit and size decide whether a T-shirt gets worn or forgotten in a drawer. Choose the right fit for the wearers, compare garment measurements rather than labels, plan size splits from real data, insist on pre-shrunk fabric and wash testing, and give clear care instructions. Do these things well and your T-shirts will fit on the first day and the hundredth.

Planning a staff, team or retail T-shirt order? Ask Dsigngo Group for size charts and fit samples.

Request Size Charts

Related reading

• Custom T-Shirt Manufacturing: A Complete Guide from Idea to Delivery
• T-Shirt Fabrics Explained: Cotton Types, GSM, Blends and Organic Cotton
• Screen Printing, DTF, DTG, Embroidery and More: T-Shirt Decoration Methods Compared
• How to Prepare Artwork for T-Shirt Printing: Files, Resolution, Colours and Placement
• Corporate, Event and Team T-Shirts and Polos: A Buyer's Guide to Bulk Orders
• How Denim Jeans Are Made: From Cotton Field to Finished Pair

Sources

• Teepig, "Which t-shirt?" guide on fits, sizing, shrinkage and care: https://www.teepig.co.uk/help/which-t-shirt/
• ISO 3758, textiles care labelling code using symbols.
• Regulation (EU) No 1007/2011 on textile fibre names and labelling.