Pool Surface Area Calculator

From one set of plan dimensions and the depth pair we compute every measure a pool job needs — the two areas a heater/cover shopper and a resurfacer each mean by "surface area," kept side by side and labeled so they can never be confused. The average depth is the mean of the shallow and deep ends; leave the deep end blank for a constant-depth pool.

avgDepth = (shallow + deep) / 2   (deep blank ⇒ avgDepth = shallow)

Water-surface (top face) area:
  rectangle:  L × W
  round:      π × (D/2)²
  oval:       π × (D1/2) × (D2/2)
  kidney:     0.45 × (A + B) × L          (approximation)

Total interior wetted area (floor + 4 walls — rectangle only):
  (L × W) + (L × avgDepth × 2) + (W × shallow) + (W × deep)

Perimeter / waterline length:
  rectangle:  (L + W) × 2
  round:      π × D
  oval:       π × (D1 + D2) / 2           (approximate)
  kidney:     (L + max(A, B)) × 2         (rough estimate)

Waterline tile band:
  band area       = perimeter × band height
  incl. waste     = band area × (1 + waste%)

We use π = Math.PI (not 3.14), so the round and oval figures are exact for the circle and ellipse. The total wetted interior area ships for rectangular pools only — the floor-plus-four-walls formula is published for rectangles, and we do not invent an unsourced wall-wrap for curved shapes; measure those in sections. The kidney top face uses the accepted 0.45 area factor, and the oval and kidney perimeters are approximations (a mean-diameter circle and a bounding box) — verify the actual waterline before ordering tile. Results are planning estimates from your measurements, not a survey or takeoff of record.

Sources: INYOPools — Swimming Pool Calculations (per-shape top-face formulas); PoolTile.ca — How to Measure and Calculate Your Pool Size (floor-plus-four-walls, perimeter, tile band, and the 1,088 ft² worked example).