Tool
Lake and Pond Calculator
Map your lake or pond, estimate its depth and volume, then build a fish stocking plan, a habitat plan and a floating island plan sized to your water.
Step 1
Find and outline your pond
Search for your property, then draw the outline of the water. Everything below builds on this map.
Zoom in until the shoreline is sharp, then press Draw pond outline and tap around the edge of the water. Trace the water line, not the bank. Press Finish outline when you are done.
When you finish an outline, Living Waters Environmental saves its location, size and your results. Privacy policy
Step 2
Depth
Enter the deepest spot you know of and pick the shape that best matches the bottom. We use these to estimate average depth and volume.
Your pond is too narrow for 3:1 sides at this depth, so the deep V estimate is shown.
Depth and volume here are calculated from your maximum depth and a typical pond shape, not measured. Real ponds have shelves, holes and silt that change the numbers. For accurate depth, volume and contour maps, see our sonar lake mapping.
Step 3
Fish stocking plan
Pick the fish you want. The plan sizes each species to your pond and keeps predators and prey in balance.
Outline your pond and enter a maximum depth to unlock this tool.
Fish you want
Choose one or more.
Step 4
Fish habitat
How much cover your pond can use and where it goes, based on your size, depth and the fish you picked.
Outline your pond and enter a maximum depth to unlock this tool.
How it is sized
Counts come from published extension and agency guidelines, multiplied by your surface acres. Each line is a separate option, so pick one or two types rather than adding them all together.
Cover works best between 4 and 10 ft. In summer, the deep water of a pond without aeration may hold little oxygen below about 12 ft, so keep structures shallower than that.
Step 5
Floating islands and phosphorus
Pick an island size to see how much of your pond it covers and roughly how much phosphorus it can take up each growing season.
Outline your pond and enter a maximum depth to unlock this tool.
Island size
Phosphorus is the nutrient that most often limits algae and plant growth in ponds. A widely used rule of thumb is that one pound of phosphorus can grow up to 500 pounds of wet algae.
Optional
Have a specialist review your plan
Send your pond and results to our team. We will look it over and get back to you with what we would check first.
When you outline a pond, Living Waters Environmental saves its location, size and your calculator results so our team can help with your water. Contact details are only saved if you enter them. See our privacy policy.
Surface area
The outline you trace is measured on the curved surface of the earth, the same way mapping software measures area. Careful tracing along the water line on satellite imagery gives a good surface area. Water levels change through the year, so trace the level you want to plan around.
How depth is estimated
For a dug pond with 3:1 sides, we assume sides that slope about 3 feet out for every 1 foot down until they reach your maximum depth, then level off. If the pond is too narrow for those sides to reach the maximum depth, the deep V estimate is shown instead. For gradual slopes, typical of natural ponds, the average depth is about half the maximum. For a deep V or bowl, the pond gets steadily deeper toward one spot, which puts the average depth at about a third of the maximum. These shapes are simplified, so treat the result as an estimate. Shelves, holes and built up silt can move the real numbers a lot.
Our sonar lake mapping records depth across the whole pond for an exact volume, contour maps and the area at every depth.
Why predator to prey ratios matter
A pond can only grow so many pounds of fish. With too few predators, sunfish overpopulate and stay small. With too many, bass run out of food and grow slowly. Published stocking rates hold a ratio of about 10 sunfish for every bass, which is why the calculator adds or asks for a predator or prey species when your picks would fall out of balance. If you already have fish, Eco-Fish mapping shows what is there before you add more.
Island phosphorus estimates
Plant roots hanging under a floating island, and the film of microbes on them, take up nutrients from the water. Studies measure very different rates depending on plants, climate and how much phosphorus is in the water, so the calculator shows a range rather than one number. Floating islands work best as one part of a plan that also limits incoming nutrients.
Sources. Chesapeake Bay Program, Floating Treatment Wetlands Expert Panel (2016). Lynch and others, Ecological Engineering (2015). US EPA, Floating wetlands for urban and agricultural runoff. UW Extension Lakes, Lake Tides.
Want exact numbers?
Map your lake with sonar
Sonar lake mapping measures depth across the whole pond for an exact volume and detailed depth maps.