How to measure and weigh a parcel properly

Carriers check sizes and weights with automatic machines. If your parcel is bigger or heavier than you paid for, you may be charged a surcharge, or the parcel may be returned or held until the recipient pays. A couple of minutes with a tape measure and scales avoids all of that.

Measure after packing

Always measure the parcel exactly as you will send it – with the box or bag, padding, tape and label. Bulging boxes count at their biggest point.

Length, width and depth

1. Length is the longest side.
2. Width is the next longest side.
3. Depth (or height, or thickness) is the shortest side.

Round up to the next whole centimetre. If your item is 35.4cm long, it won't fit a 35.3cm Large Letter limit.

Check the thickness of letters

For letters and large letters, thickness is what catches people out. A standard Letter must be 5mm or less; a Large Letter must be 2.5cm or less. A cheap plastic size-guide template makes this instant, or you can make your own by cutting a 2.5cm slot in a piece of card.

Length plus girth

Some couriers, such as Evri, also set a limit on length plus girth. Girth is the distance around the parcel: 2 × width + 2 × depth. For a box 60 × 40 × 30cm, length plus girth is 60 + (2 × 40) + (2 × 30) = 200cm. Our calculator checks this for you.

Weighing

• Kitchen scales work for letters and small parcels up to a few kilograms.
• Digital parcel scales are flat platforms that handle up to 30kg or more and are accurate to the gram – worth buying if you post regularly. See our recommended supplies.
• Bathroom scales trick: weigh yourself, then weigh yourself holding the parcel, and subtract. Fine for heavy parcels, but not precise enough near a weight limit.

Volumetric weight

Some couriers, especially for international and express services, charge by volumetric (dimensional) weight if it's higher than the actual weight. It's usually calculated as length × width × depth (cm) ÷ 5000. A large, light box of 50 × 40 × 40cm has a volumetric weight of 16kg, even if it only weighs 3kg. Use the smallest box that safely fits your item.