The phrase "this is calculated by" is correct and can be used in written English.
You can use this phrase when you want to explain how something is calculated. For example, "The distance between the two towns is calculated by using the Pythagorean theorem."
This is calculated by the Living Wage Foundation (pdf) and is based on the cost of living – not to be confused with the government's lower national living wage.
This is calculated by using an approved methodology to subtract the estimated emissions of a given project from a hypothetical 'business-as-usual' emissions baseline.
This is calculated by adding on the extra hours workers would like to work at the going wage rate.
Under a longstanding New York tradition, landlords use a formula to charge tenants extra for common space in their buildings, like lobbies and stairwells, that cannot rented out; this is calculated by adding a fixed percentage to the actual measurement.
This is calculated by focusing on the Americans who, when surveyed at some point between 1978 and 1997, were in the bottom half of the income distribution — that is, they earned less than the median American.
This is calculated by dividing a start-up's estimated worth (derived from venture-funding rounds, equity transactions on secondary markets and so on) by the number of its users.By this benchmark, Groupon scores well, just below Facebook and Renren, a Chinese social network with a listing in America (see chart).
How crowded This was calculated by dividing skiable surface by the lift capacity.
Damages in a claim like this are calculated by looking at the amount lost as a result of the securities fraud.
This was calculated by equation E-1 from the modeled responses RP and RK: (1).
This was calculated by integer numbers between 0 and the highest proposed value: (Eq. 4).
This was calculated by adding up the area of maize and OSR cropland within a radius of 800 m (maize) and 4,000 m (OSR) around the NSG.
