The phrase 'calculated how much' is correct and can be used in written English.
For example: "The accountant calculated how much money the company had earned this quarter."
I know this because I once calculated how much soup I served from it.
The researchers calculated how much oxygen should have diffused into each layer of the sediment.
He said he and his son calculated how much they pay in taxes.
It may spend millions to help distribute Bactrim, but has not yet calculated how much to commit.
Finally, they calculated how much of the species' "climate envelope" would be left under different warming scenarios.
If I calculated how much I spend doing this it would scare the bejesus out of me".
Part of that would ultimately save money for employers, but the Congressional Budget Office has not yet calculated how much.
The bank's economists first calculated how much growth was explained by a bigger workforce and how much by more plant.
Then they calculated how much the temperature in each cell deviated from the cell's reference value in any given summer.
Harvard Business School's Mr Khurana has calculated how much riskier the boss's job has become in America.
The preparers also calculated how much aid the student could get, and provided figures for tuition costs at nearby colleges.
