Transfermarkt estimate it at around £430m before Enzo. Based on an average contract length of 6 years and with approx half the spending coming in January, from an amortisation pov (the expense that matters re FFP) even including the £110m(ish) on Fernandez, these signings will cost Chelsea circa £60m on this years accounts.
Ignoring any other sales Chelsea have made this season, if Chelsea shift Connor Gallagher for the reported £40m fee that's being talked about, Chelsea will make a profit on his sale of £40m on this seasons accounts. So when people ask how can Chelsea spend all this and comply with FFP, this is how.