At certain temperature the value of pK_w is 13.4. The measured pH of a solution at same temperature is 7. The solution is:

${\mathrm{K}}_{\mathrm{W}}=\left[{\mathrm{H}}^{+}\right]\left[{\mathrm{OH}}^{-}\right]=13.4$

In neutral water, $\left[{\mathrm{H}}^{+}\right]=\left[{\mathrm{OH}}^{-}\right]$

pH of neutral water, then, is 6.7.
As a result, solutions with pH values greater than 6.7 will be basic in nature, while those with pH values lower than 6.7 will be acidic.