I'm wondering whether to set up a website which does these sort of calculations.
It may help to set out here how to do these calculations.
Step 1- work out the annual salary for someone who works one hour a week.
In this case if the annual salary is �20,261 for a 37.5 hour week then the annual salary for a one hour week would be �20,261 divided by 37.5, which equals �540.29.
Step 2- multiply up by the appropriate number of hours.
So for 28 hours you multiply �540.29 x 28. This gives �15,128