Royal Mail applies the industry-standard 5000 cm³/kg divisor for most international services. Domestic UK services (1st/2nd Class) typically use weight-only pricing without a volumetric component.
Awaiting dimensions. Enter package details to compute billable weight.
| Service | Imperial (in/lb) | Metric (cm/kg) | Notes |
|---|---|---|---|
| International Tracked | — | 5000 | All packages |
| International Signed | — | 5000 | All packages |
| Business Parcels (BPL) | — | 5000 | All packages |
UK-origin international parcels, EU and Commonwealth destinations
Domestic UK (use 1st/2nd Class · no DIM weight)
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Royal Mail uses a divisor of 5000 cm³/kg (metric) — this carrier publishes only metric divisors. The DIM weight formula is volume divided by this number, rounded up to the nearest whole pound or kilogram.
Royal Mail applies dimensional weight to packages above No minimum. The billable weight is always the greater of the actual weight or the calculated DIM weight.
Use right-sized packaging — every cubic inch you save is divided by the divisor and removed from your billable weight. Avoid excessive void fill and consider custom box sizes for products you ship frequently. For occasional shippers, use the calculator above to test packaging changes before you commit to new materials.