If you don’t have the volume to hand, you can estimate the size you’ll need from the person’s body weight before cremation. As a general rule, every 1lb (0.45kg) of body weight needs roughly 1 cubic inch — about 1.7cl — of urn capacity.
This is a guide rather than an exact science, and the final volume varies from person to person. A few things worth keeping in mind:
- Taller or larger-framed people may need a little extra capacity.
- For a stillborn baby or a young child, you may need slightly more than weight alone suggests.
- Body fat largely burns away during cremation, so it has less effect on the final volume than you might expect.
As reassurance: most of our standard single adult urns hold around 280–340cl (2.8–3.4 litres), which comfortably suits the great majority of adults — so in most cases a standard adult urn is all you need.
| Weight before cremation | Urn capacity needed (approx.) | Approx. weight of ashes |
|---|---|---|
| Up to 5 st (32 kg) | ~120 cl (1.2 L) | ~0.9 kg |
| 8 st (51 kg) | ~190 cl (1.9 L) | ~1.5 kg |
| 10 st (64 kg) | ~240 cl (2.4 L) | ~1.8 kg |
| 12 st (76 kg) | ~285 cl (2.85 L) | ~2.2 kg |
| 14 st (89 kg) | ~335 cl (3.35 L) | ~2.5 kg |
| 16 st (102 kg) | ~380 cl (3.8 L) | ~2.9 kg |
| 18 st and above (114 kg+) | ~430 cl+ (4.3 L+) | ~3.3 kg+ |
