Wound Depth & Graft Size Calculator

Based on Dr. Shaun Carpenter's True-Graft Conformable Drape Method

Select Measurement Method

Grid Overlay Method

Place the conformed drape template over a 1 cm² wound measurement grid and count the squares.

For 0.5 cm fixation edge calculation

Bounding Rectangle Method

Measure the longest length and widest width of the conformed drape template laid flat.

For 0.5 cm fixation edge calculation. If left blank, perimeter is estimated as 2(L+W).

Elliptical Approximation

For roughly oval wounds. Measure the major and minor axes of the conformed drape template.

If left blank, perimeter is approximated using Ramanujan's formula.

Traditional Method (L × W × D)

This box-model method can overestimate wound volume by 2–3×. Shown here for comparison only.

How the True-Graft Method Works

1

Conform

Lay a sterile surgical drape over the wound. Press it into the full wound bed — depth, tunnels, undermined areas — the way a graft would sit.

2

Trace

With a marking pen, trace the wound edges on the drape. Add ~0.5 cm border for fixation onto healthy skin.

3

Measure

Remove the drape and lay it flat. The traced outline is now a 2-D template of the true 3-D wound surface. Measure using grid, ruler, or digital planimetry.

4

Order

Enter measurements above. The calculator recommends the smallest standard graft sheet that covers the wound.

Core Formula

Graft Area = Aconform + (Perimeter × 0.5 cm)

Where Aconform is the area of the drape after it has been conformed to the wound bed, and the perimeter term accounts for the fixation overlap.