=INT(A1/100)+MOD(A1,100)*5/300

HTH. Best wishes Harald

"Sean Skallerud" skrev i melding
...
One of the pieces of software we use gives us time in an awkward format.
16633 means 166 minutes 33 seconds. I need a formula to convert this
figure
to a decimal respresentation of time (166.55 for the example listed
previously).

Any help will be much appreciated.