How to Choose the Right Size When Shopping Online

Shopping online for baby clothes is wonderfully convenient, but getting the right size can be tricky. Sizing varies between brands, babies grow at different rates, and you cannot try anything on before it arrives. Here is our practical guide to choosing the right size every time.

Measuring Your Baby

Before you start shopping, take accurate measurements of your baby. You will need:

• Height/length — Lay your baby flat on their back and measure from the top of the head to the sole of the foot
• Chest — Measure around the fullest part of the chest, under the arms
• Waist — Measure around the natural waistline
• Weight — An up-to-date weight helps with age-based sizing

Use a soft tape measure and try to take measurements when your baby is relaxed and still — after a feed or during a calm moment often works best.

Understanding Size Charts

Most baby clothing is sized by age (for example, 0–3 months, 3–6 months, 6–12 months), but age is only a rough guide. A more reliable approach is to compare your baby’s actual measurements against the brand’s size chart. Look for size charts on the product page or in the retailer’s help section, and always use the measurements in centimetres rather than relying on age alone.

Allowing Room to Grow

Babies grow at an astonishing pace, particularly in the first year. A garment that fits perfectly today may be too small in just a few weeks. When choosing between two sizes, it is almost always better to go with the larger option. Slightly roomier clothes are more comfortable for your baby and will get more wear before being outgrown.

Brand Sizing Differences

One of the biggest challenges of shopping online is that sizing is not standardised across brands. A 3–6 months garment from one brand may fit quite differently from the same size in another. To navigate this:

• Check customer reviews for comments about sizing (phrases like “runs small” or “generous fit” are very helpful)
• Note which brands fit your baby well and use them as a benchmark
• If a brand is new to you, consult the size chart carefully rather than assuming

When to Size Up

There are a few situations where sizing up is particularly wise:

• Growsuits and sleepsuits — Your baby needs room to stretch and kick comfortably
• Outerwear — Jackets and coats need to fit over layers
• End of season purchases — If buying ahead for the next season, go up a size to account for growth

Check the Returns Policy

Even with the best planning, sometimes a size just does not work out. Before purchasing, always check the retailer’s returns policy. Look for free returns, a reasonable return window and clear instructions for exchanges. A good returns policy takes the worry out of ordering online.

At TJ Clothes, our product pages include detailed size guides to help you find the perfect fit. Our sizes follow standard UK baby sizing, and our customer service team is always happy to help if you are unsure. Shop with confidence, knowing that getting the right size is easy.