The official free calculator from Amazon Services Europe where you can work out the total amount credited to your account.

https://sell.amazon.co.uk/sell-online?ref_=asuk_soa_rd&ld=SEUKSOAAdGog_10330351415_102557516843_kwd-763866159504_b_443092606069_c_asret_&id=go_cmp-10330351415_adg-102557516843_ad-443092606069_kwd-763866159504_devc_ext-_prd-