You make the rockin' world go round

Today's really flippin' weird request:

I would be most grateful if anyone who has the time, has the inclination, and is able without great effort or personal inconvenience, could measure their toilet seat. And comment to tell me the results.

The dimensions I would like to know are the front-to-back measurement and side-to-side measurement of the "hole" part of the seat. Although places like B&Q online list dimensions, I think they're overall dimensions and I specifically want to know about the size of the hole.

Assuming no one is likely to want to measure more than one, info about whether your chosen data point is in your home, an office, or somewhere else might be useful. Any details of colour, vintage, paddedness of seat, etc are left entirely up to you. Units as preferred by the measurer (preferably sensible ones, if anyone claims they do all their DIY in parsecs I shan't believe them).

(Reasons for asking, if you care, to be revealed in due course...)