It is essential to record in the nursing notes an accurate account of the wound's state at agreed time periods, to check the progress of healing in order to determine whether improvement or deterioration is occurring . Wound mapping is a useful way to measure the surface area of a wound, though it is more suitable for measuring shallow, superficial wounds, as the depth and volume of a wound is not taken into account by this method.

The circumference of the wound can be traced on to a transparent material such as acetate or plastic using a fibre-tipped pen although acetate is not very flexible and is nonsterile . Many of the transparent film dressings now have a measuring grid built into the packaging so that sterility of the wound contact is maintained whilst measurement is done. The contact layer is then disposed of leaving the uncontaminated grid behind to be attached to the nursing notes. The accuracy of the measurement is heavily dependent on the practitioner's judgement of the perimeter of the wound. Nonetheless, as a baseline to chart progress of the expansion or contraction of the wound surface area, it can be a valuable assessment tool.

The surface area of the wound can then be roughly calculated by counting up the number of complete squares (usually measured in 1 cm ² squares) .  The remaining squares that fall inside the wound perimeter and who's area is equal or greater than 1/2 cm ² are counted as 1/2 cm ² . Adding these two figures together gives an approximate wound surface area in centimeters squared. Due to the possible margin for error it would be desirable to have the same practitioner perform the wound mapping to maximize the accuracy of this procedure.