Contact us
Found a mistake, have an idea for a new calculator or a question about how one works? Email us. We read everything and usually reply within a few days.
Or start an email about a specific topic:
If you’re reporting a mistake, it helps to include the page, the numbers you entered and the result you expected.
We can’t give medical advice for your pet. If your pet may be poisoned or is unwell, call your vet or an emergency clinic now.