Revaluation Rate : Is there a way to carry out the revaluation process with knowing only the revalue

because, in our business,when revaluing assets such as lands,the revaluer gives the amount that should be increased. Since  manually doing the back calculation to arrive at a revaluation rate is very time consuming, i'd like to know whether its possible to automate the rate conversion in the revaluation process when an amount is given.

Thank You