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Pond Calculator: Volume, Acreage & Stocking

Work out what your pond holds and what it can support — gallons, acre-feet, surface acres, and classic bass/bluegill/catfish stocking numbers.

Basis: Alabama & Mississippi State Extension · reviewed July 2026

Pond volume & surface area

New-pond fish stocking

How the pond math works

Volume: surface area × average depth gives cubic feet; multiply by 7.48 for gallons. The trick is average depth — ponds aren't swimming pools. On a typical embankment farm pond (max depth measured at the dam), average depth runs about 40% of maximum depth — the approximation Alabama Extension uses; the steeper/gradual presets are our planning heuristics. One acre-foot (an acre, one foot deep) is 325,851 gallons.

Before treating your pond with chemicals: many water-column treatments are dosed from acre-feet, but others use surface acres, concentration, or spot-treatment area — always follow the product label. And don't use a rough profile estimate for products with a narrow safety margin; measure actual average depth first.

Stocking: the Southeastern extension baseline for a balanced largemouth bass–bluegill fishery in a new, unfertilized pond is 50 bass + 500 total bream per surface acre (commonly 350 bluegill + 150 redear sunfish), stocking the sunfish in fall and the bass the following spring so the forage base is established first. Channel catfish are optional at 25–50/acre and usually need restocking as they're caught. A managed fertilization program roughly doubles those rates (per MSU guidance) — supplemental feeding alone does not.

State recommendations vary. Northern states with shorter growing seasons often recommend different species mixes (e.g., adding fathead minnows, skipping fertilization). Your state wildlife agency or extension fisheries specialist publishes a free stocking guide — worth a read before you order fish.

Quick reference

MeasureValue
1 acre43,560 sq ft
1 acre-foot325,851 gallons
1 cubic foot7.48 gallons
Avg depth (bowl pond)≈ 0.4 × max depth
New pond stocking (per acre, unfertilized)50 bass + 500 bluegill/redear (+25–50 catfish optional)

Frequently asked questions

Why does volume matter? Pond chemical treatments (herbicides, lime, fertilizer) are dosed per acre-foot. Aeration systems are sized by volume and depth. Guessing wrong wastes money or fish.

When should I stock? The proven sequence: bluegill/redear (and fathead minnows) in fall, largemouth bass the following spring. Stocking forage fish first lets them grow and reproduce before bass arrive, greatly reducing the risk of an imbalanced population.

Sources

  • State extension pond management guides (e.g., Texas A&M AgriLife, Auburn/Alabama, Mississippi State)
  • USDA NRCS pond design references