The VAT calculator itself does not collect personal data at the moment.
Our advertising partners and their partners and their partners do all that's in their power to track you to provide more relevant ads.
We are using Google Analytics to collect data to understand our visitors better. To us, it's all anonymous data. To Google... well, they serve ads for a living, don't they?
We are not storing anything you input into calculator, but it may make sense to do it in the future.