The figures were shared at a county council cabinet meeting where members were updated on the impact of the pandemic on the area.
Amanda Jupp, cabinet member for adults & health, told members there had been 895 recorded cases of the virus in West Sussex.
While Mrs Jupp said she did not yet have the figures showing how many people had died, data from NHS England said the five health trusts covering East and West Sussex had reported 361 Covid-19 related deaths up to April 21.
The meeting was told that, in West Sussex, more than three-quarters of those people died in hospital, 18% in care homes, 2% at home, 1% in hospices, and 1% elsewhere.
There were concerns from some about patients moving from hospitals to care homes without being tested for Covid-19.
Lib Dem leader Dr James Walsh said he had learned that testing only started last Friday, after a change in government guidance.
Dr Walsh said this was ‘an incredibly dangerous situation to have got ourselves into’.
Looking at the economic impact on the county, Katharine Eberhart, director of finance, said the estimated cost of a three-month lock-down could be as much as £85m.
Before the pandemic, the council was preparing for a budget shortfall of £45m between 2021 and 2024.
Now Ms Eberhart warned there would be financial implications stretching beyond 2020/21 and bringing ‘significant’ costs in future years.
So far, West Sussex has received £20.5m of government emergency money and is waiting to find out what portion of the next round of funding will come to the county.
Ms Eberhart said: “It’s easy to work out that the proposed funding from government currently is actually not likely to cover our costs – and we have no idea what that might mean for us in the future.”
Painting a bleak picture of that future, she added: “If government doesn’t provide adequate additional funding, this will result in the cost of Covid falling on the local population and perhaps subsequent decisions where we’re going to need to redo services and staffing in order to ensure that we can meet a balanced budget.”
Ms Eberhart said most of the extra costs centred around adult social care and the increased demand for residential care, while there had also been an increase in children’s services costs.
Savings planned for this year will be ‘slower to get off the ground’ while the lack of business rates and drop in council tax payments as more people apply for Universial Credit would also hit hard.
There was much-deserved praise for the way council staff had been handling the lockdown.
CEO Becky Shaw said: “We have been working absolutely relentlessly for over five weeks now to deliver our key objectives – firstly to save lives, second to protect the vulnerable, thirdly is to keep critical services in place, and lastly but not least importantly, is to make sure we’re ready to be able to make an effective recovery.
“This emergency has placed the most extraordinary demands on staff right across the council and they have willingly, relentlessly and selflessly taken on new roles and very different roles working in different places and with different teams.
“They’ve responded cheerfully, positively and have adapted quickly.”
Praising the ‘extraordinary’ work of the social care staff, she added: “I’m incredibly proud of all that the staff have done and will do.
“We will take the learning, the creativity, the energy and the spirit that we have done this work with as we work out all that will follow.”
Karen Dunn , Local Democracy Reporting Service