Is there a per country estimation of the GDP drop due to COVID?

There are some cross-country studies but not that many of them yet. For example, Maliszewska, M., Mattoo, A., & Van Der Mensbrugghe, D. (2020) from world bank provide some cross-country estimates of the cumulative effect of covid-19 for various countries and regions across the world. Their estimated cumulative effect of covid on GDP (measured as deviation from their benchmark) is shown below.

However, I would advise to take these results with a pinch of salt. These are preliminary estimates that were published in April and better ones will be fore sure forthcoming in near future.