Ordering a personalised T-shirt? Learn how to measure chest width and length, understand unisex sizing, choose between sizes and avoid costly sizing mistakes.
Choosing the right size is one of the most important parts of ordering a custom T-shirt. Once a garment has been personalised, changing your mind about the fit is usually much harder than returning an ordinary undecorated tee.
The safest method is simple: take a T-shirt you already like, lay it flat, measure its chest width and body length, then compare those measurements with the size chart for the exact garment you are ordering. Do not rely on the letter S, M or L alone.
T-shirts and custom apparel
This garment-to-garment comparison is widely recommended by UK clothing retailers because it avoids confusion between body measurements and flat garment measurements.
A Medium in one T-shirt can fit like a Small or Large in another. The size label is only a category; the actual fit comes from the garment pattern and measurements.
Current UK size guides illustrate the variation clearly. Some unisex Medium T-shirts measure around 50–52 cm across the chest when laid flat, while oversized cuts can be substantially wider. Body length, shoulder shape and sleeve position can also vary even when two products carry the same size letter.
That is why ElitePrints customers should check the size guide for the specific blank garment, especially when ordering for a team, merchandise launch or event.
This is one of the most common sources of sizing mistakes.
A body chest measurement is taken around the fullest part of your chest with a tape measure. A half-chest garment measurement is the width of a T-shirt laid flat, measured from one side to the other under the armholes.
They are not interchangeable.
If a size chart says a T-shirt has a half chest of 52 cm, that does not mean it fits a 52 cm body chest. It means the garment itself is approximately 52 cm wide across the front when flat. Doubling that gives roughly 104 cm around the garment before allowing for construction, fabric behaviour and fit.
Always check whether the chart says to fit chest, garment chest, width, half chest or pit to pit.
Use a shirt that already fits the way you want. If you want your custom tee relaxed, do not measure a fitted gym shirt. If you want a neat staff uniform, do not measure your largest oversized streetwear tee.
Place the garment on a flat surface and smooth out major wrinkles without stretching the fabric.
Measure horizontally across the chest from one armpit area to the other. Many size guides call this width or half chest.
Keep the tape straight. Measuring diagonally can add several centimetres and push you toward the wrong size.
Measure from the highest point of the shoulder beside the collar down to the bottom hem. Some brands measure from the back collar instead, so follow the diagram or wording supplied with the product.
Chest width is usually the first measurement people check, but length matters too. Two shirts can have a similar chest width while one is noticeably longer.
For shorter wearers, an oversized size may create much more body length than expected. For taller wearers, sizing down for a closer chest fit can make the garment too short.
Both can help, but measuring a T-shirt you already like is often easier when buying another casual T-shirt online.
Body measurements tell you about your body. Garment measurements tell you about the finished product. Comparing one garment with another gives you a direct reference for how much room and length you personally find comfortable.
If the supplier provides only a to-fit chest measurement, then measuring around your body may be necessary. Keep the tape level around the fullest part of the chest and do not pull it excessively tight.
Unisex usually means the garment is built around a general adult cut rather than a specifically fitted men's or women's pattern. It does not mean every unisex T-shirt fits the same.
A standard unisex tee may look relatively regular on one person and loose on another. A deliberately oversized unisex tee can be much wider through the body and have dropped shoulders even at the same labelled size.
This matters for group orders. If a company simply asks everyone for their “normal size” without showing the actual garment chart, people may be expecting completely different fits.
For staff clothing, clubs and events, share the exact product size chart before collecting sizes.
A regular fit usually follows the body without being extremely tight. It is a versatile choice for staff clothing, events and everyday custom T-shirts.
A relaxed tee gives more room through the chest and body. It can feel more casual and may be easier to wear across different body shapes.
Oversized garments are intentionally wider and often use dropped shoulders and extra body volume. Buying one or two sizes larger in a regular-fit T-shirt does not always create the same look because the pattern proportions are different.
If you want an oversized result, choose a garment designed as oversized where possible rather than relying only on sizing up.
There is no automatic answer. Ask what you want the finished garment to do.
Choose the smaller size when the chart confirms enough room and you prefer a closer, neater fit. Choose the larger size when you prefer more movement, plan to layer the T-shirt, or the product description says the style fits small.
Several UK size guides advise sizing up when between sizes, particularly for closer-fitting technical garments. But that is not a universal rule. A boxy or oversized product may already contain substantial ease.
The actual measurements should decide.
Cotton garments can change dimensions after laundering, although the amount depends on the fabric, manufacturing process and care routine. Do not deliberately buy a much larger size on the assumption that it will shrink to fit.
Follow the garment care label and the printer's decoration-care guidance. For many printed T-shirts, washing cool and avoiding excessive tumble-dryer heat is also gentler on the print.
If fit is critical for a retail collection or large uniform order, wash-test a decorated sample before committing to the full quantity.
Textile garments are not machined metal parts. Small measurement differences between individual pieces are normal.
Current UK retailers commonly state tolerances around 1–2.5 cm, depending on product and manufacturer. This means a chart showing 52 cm half chest should be treated as an approximate specification rather than a guarantee that every garment will measure exactly 52.0 cm.
For ordinary clothing this variation is usually minor, but it matters when someone is choosing a size with almost no spare room.
Not automatically.
Many custom-printing workflows use the same physical artwork size across several adult garment sizes. A 28 cm-wide design therefore occupies more visual space on a Small than on a 2XL.
This is why sizing and print placement are connected. If a group order ranges from XS to 5XL, you may want to discuss whether one print size is acceptable across the full range or whether artwork should be scaled in size groups.
For most straightforward orders, consistent artwork size works well. For fashion merchandise or very large size ranges, proportional scaling may create a more balanced appearance.
Do not guess the whole team's sizes from job titles, age or appearance. Share the garment chart and collect each person's selection.
A practical process is:
This is especially useful for growing businesses because a later new starter can order against the same known garment rather than restarting the sizing process.
For events, collect sizes during registration whenever possible. Real attendee data is more reliable than a generic size percentage.
If you need spare stock, Medium and Large often account for substantial shares of general unisex orders, but your own audience should take priority. A university event, construction workforce and children's charity event will not have the same distribution.
Also remember that the fit itself affects the size split. People may choose differently when the product is a fitted performance top rather than a relaxed cotton tee.
A clothing brand has two sizing problems: helping the customer choose correctly and deciding how much stock to hold.
The product page should clearly state:
For a first merchandise drop, consider a small run or pre-orders rather than guessing a large size curve. Actual sales data is much more valuable for the second order.
With ordinary online clothing, a buyer may order two sizes and return one. Customised garments are different because they are made specifically for the order.
That makes pre-order sizing checks more important. Before approving personalised clothing, confirm the garment style, colour, size, artwork and placement together.
For a large team order, a plain sizing sample can be cheaper than discovering after decoration that several people selected the wrong fit.
It is not. Check measurements for the exact garment.
Read the chart heading carefully. A 50 cm half chest is not a 50 cm body circumference.
Length and shoulder shape can completely change how a T-shirt feels.
A larger regular-fit shirt may become longer without creating the intended boxy proportions.
Do not choose a garment that only fits if every piece lands at the smallest possible measurement.
Collect actual sizes whenever you can.
A fixed-size design looks different across XS and 3XL garments.
For online custom T-shirt orders, use this sequence:
Favourite T-shirt → measure flat → compare chest width → compare length → check fit description → choose size.
For group orders:
Choose exact garment → distribute its size chart → collect individual sizes → verify unusual/edge cases → decorate only after confirmation.
This is much safer than converting everyone's normal high-street size into a new garment without checking measurements.
For a garment measurement, lay the T-shirt flat and measure straight across from armpit to armpit. This is usually called half chest, width or pit-to-pit. For a body measurement, wrap the tape around the fullest part of your chest while keeping it level.
It means the garment measures approximately 50 cm across the chest when laid flat. It is not a 50 cm body-chest measurement.
Only if the product measurements and your preferred fit support it. If you are between sizes or want a relaxed fit, sizing up may be sensible. If the garment is already oversized, your usual size may already provide substantial room.
They often have a straighter and roomier cut, but exact measurements vary by product. Compare the two charts rather than converting sizes by assumption.
Use the oversized garment's own chest width and length measurements. Do not assume you need to order above your usual size; an oversized pattern is already designed with extra room.
Return rights for personalised goods differ from ordinary stock products, and policies vary by seller. Check the supplier's terms before ordering. This is another reason to verify measurements before decoration.
For a substantial order, samples can be worthwhile because staff can check the real garment rather than interpreting a chart differently. The value increases when the chosen product is fitted, oversized or unfamiliar to the team.
The most reliable custom T-shirt size is not the letter you usually buy. It is the size whose actual garment measurements match a T-shirt you already know fits well.
Measure pit to pit. Check body length. Understand whether the chart describes the garment or your body. Pay attention to regular, relaxed and oversized cuts. Allow for normal manufacturing tolerance and do not assume a bigger size automatically creates a better oversized silhouette.
For teams and events, collect individual sizes against the exact product chart rather than guessing. For merchandise, make sizing information clear enough that customers can compare measurements before ordering.
ElitePrints can help customers choose suitable custom T-shirts and other garments before production. Getting the fit right before the artwork is printed protects the value of the order — and helps ensure the finished T-shirt is something people actually want to wear.
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