**Estimating the age of a foetus**

When a foetus is aborted or born mummified, it is sometimes useful to estimate the age at which the foetus died.

This simple spreadsheet provides a rough guide based on the formulae:

((Crown/rump length mm)/3)+21

Insert the length of your foetus in the yellow box

A more accurate formula is ((crown/rump length)/3.11)+21.07