Use clothes that fit now to choose the next size

Your best tape measure is in the drawer

Measuring a baby is fiddly: they curl up, kick and roll away. Measuring a piece of clothing that already fits them well is easy, and it tells you something a body measurement can’t: how much room your baby likes, in the kind of piece you are buying.

Pick one favourite that fits right now, not one that is tight or one they are growing into. Ideally choose the same type as the piece you plan to buy: a sleepsuit to choose a sleepsuit, a set to choose a set.

How to lay it flat

• Use a table or the floor, not a bed, so the fabric can’t sink.
• Close all the snaps, buttons and zips.
• Smooth it out gently with your hands without stretching it. Knits in particular pull longer if you tug them.
• Lay the sleeves straight out to the side or folded neatly along the body, whichever makes them lie flat.
• Use a soft tape or a metal tape measure, and note each number in centimetres.

The five measurements worth taking

Take each measurement twice and write it down straight away, with the name of the piece next to it. Knits in particular can give slightly different readings depending on how flat they lie, so if the two numbers differ, smooth the piece again and take a third. A note on your phone with “good-fitting sleepsuit, 3–6M: chest 25 cm across, length 58 cm” is something you can check against any listing in seconds.

• Chest: straight across the front from one underarm seam to the other. Double it for the measurement all the way round.
• Body length: from the highest point of the shoulder, beside the neck, down to the hem of a top, or to the crotch of a one-piece.
• Sleeve: from the shoulder seam to the end of the cuff.
• Inside leg: from the crotch seam down to the end of the leg, or the heel on a footed piece.
• Waist: straight across the waistband, relaxed and then gently stretched. Double both numbers.

Comparing with a new piece

Once you have the numbers, a new piece that measures the same will fit the same, and one that is a few centimetres longer and wider will give your baby room to grow into. When you are moving up a size, look mainly at body length and inside leg: if those are longer than the piece that fits now, the new size will last. If they are about the same, you may not be moving up at all, just into a roomier cut.

Remember that fabric changes the picture. A ribbed top like the one in our Dusty Rose Ribbed Henley & Jogger Set stretches to fit, so it can measure a little smaller than a firmer fabric and still be comfortable. Compare ribbed with ribbed where you can.

When a shop gives body measurements instead

Many size charts, including our size guide, list the baby’s measurements rather than the garment’s. Don’t compare your flat garment numbers with a body chart; the garment should always be bigger. Instead, use the garment method to understand how roomy your baby likes things, and use their own length and weight to choose from a body chart.

Sending measurements for a custom order

For a custom piece, garment measurements from something that fits well are very useful alongside your baby’s length and weight. Send the five numbers above with a photo of the piece laid flat, and tell us whether you want the new one the same, a little roomier, or made to last longer. You can start through our custom orders page; we confirm the price and making time when you ask.

For older children’s eastern wear, the same flat-lay method appears in our guide to measuring a child for a shalwar kameez.

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