As you might have seen in news reports, the government has announced (https://www.gov.uk/government/news/new-law-to-ensure-furloughed-employees-receive-full-redundancy-payments) that from 31 July all statutory notice payments (but not it seems contractual payments in excess of that) and redundancy payments for furloughed employees will be based on full 100% pay as if not furloughed, not reduced furlough pay. If this affects your calculations, you will want to take it into account. This all covers some other sums calculated on the concept of a “week’s pay”. There are some complex rules for working out pay for employees whose pay varies.