There are many. google such as ‘double glazing saving calculator’ and same for insulation, etc. My house has lots of Windows in NE Melbourne, all with honeycomb blinds. It is a 1998 build with typical insulation in the walls and roof, 2 whirly birds. I forget which calculators I used but my payback would have been a century+ ! Even the cheapest style retrofits would have been 30-40 years to do them all (not suggesting one has to do them all, but).
Be wary that most calculators you find will be US centric, almost all by businesses, and thus will be optimistic rather than conservative in payback time.
A non-quantifiable aspect is the improvement in comfort level double (or triple) glazing provides, so each to their own budgets and values of order of importance.
