The calculation of thermodynamic properties of water and steam is familiar but sometimes too slow. Some older equations with lower precisions but faster calculation speeds are therefore tested. Some new simple equations for evaluating the thermodynamic properties of water and steam are demonstrated. The deviations from precise equations are on average less than a few per cent if the calculations are made in some limited regions. Bigger deviations occur at the surrounding of the critical point and in the evaluation of the specific volume. It is shown that a quick evaluation of thermodynamic properties of water, saturated vapor and superheated steam is possible with these simple equations. The precision of the simple equations could be regulated by changing the size of the evaluated region.