How to convert a list of VMDK files into a qcow2 or img file which have the same size

I've just configured the passthrough on my ubuntu / I9 9900k / nvidia geforce RTX 2080 ti machine. Now I'm converting the VMware virtual machine VMDK files (created from the conversion of a physical installation of Windows 10) into one big qcow2 file with the following command : mario@ziomario-Z390-AORUS-PRO:/media/ziomario/DATI/DiscoC/DESKTOP-N9UN2H3# qemu-img convert -f vmdk DESKTOP-N9UN2H3*.vmdk -O qcow2 /media/ziomario/WIN/DiscoC/DESKTOP-N9UN2H3/QCOW2/DESKTOP-N9UN2H3.qcow2 The physical installation of Windows 10 has a size of 300 GB. The VMDK files produced by the conversion did with vCenter Converter have a size of 558 GB. I don't know what could be the final size of the converted qcow2 file. What I know is that I tried to save it in a disk of 1 TB and it became full. I would like to know if there is a way to convert more than one VMDK file into a qcow2 or img file (these are the formats accepted by qemu/kvm virt-manager) that will have almost the same size of the original ones. thanks.