Volumetric · Dimensional · Chargeable
Carriers bill the bigger number. Find out which one is yours.
Enter a box and its real weight. You'll get the chargeable weight, and — the part nobody else shows you — the largest box you could use before dimensional weight takes over.
Consignment
Length × width × height, in centimetres
Kilograms
Billing readout
—Enter a box to see how it will be billed.
Headroom
—
Two carriers people expect to find here
Royal Mail
Doesn't use volumetric weight for UK domestic post at all. Pricing runs on fixed format categories — Letter, Large Letter, Small Parcel, Medium Parcel — and actual weight. A big light box costs the same as a dense one in the same format band. International items routed by air can be subject to airline volumetric rules, which is a different calculation from the courier divisors above.
Evri
Prices UK domestic parcels on weight and size band rather than a published volumetric divisor. Evri does apply volumetric weight to some international destinations, but doesn't publish the divisor in the same place the couriers above do — so rather than guess, it's left out. If you need an Evri figure, get it from your account quote.
Every divisor above is taken from the carrier's own published guidance, with the date it was last checked shown next to it. Negotiated contract rates can differ from published divisors — your invoice is the final word.