Swimming Pool Volume Calculator: Measure Any Pool Shape From Satellite

Use this interactive swimming pool volume calculator to measure the exact surface area and water volume of any pool — straight from satellite imagery. Navigate to your property, draw around the pool outline, enter the depth, and get instant results in US gallons, litres, or cubic metres. Works for any pool shape: rectangular, kidney, freeform, or L-shaped.

How to Use This Pool Volume Calculator

Step 1: Navigate to Your Pool

Use the address search bar on the map to find your property. The map defaults to ESRI satellite imagery, which provides high-resolution aerial photos suitable for measuring pools. You can also switch to Google Satellite or OpenStreetMap using the layer control in the top-right corner of the map. Zoom in until your pool is clearly visible — zoom level 18 or higher works best.

Step 2: Draw the Pool Outline

Click Draw Pool (Freeform) to trace around an irregular pool shape, clicking once per point and double-clicking to close the shape. For rectangular or square pools, use Draw Pool (Rectangle) to click and drag a bounding box. The pool outline will appear highlighted in blue on the map.

Step 3: Enter Pool Depth

Choose your depth mode in the results panel below the map:

• Flat Bottom — for pools with a uniform depth throughout. Enter a single depth value.
• Shallow + Deep — for pools with a slope from shallow end to deep end. Enter both depths; the calculator uses the average as an approximation of volume.

Depth can be entered in feet (Imperial) or metres (Metric). Toggle between unit systems using the button in the toolbar.

Step 4: Read the Results

The results panel shows:

• Pool Area — the surface area of your drawn shape
• Avg Depth — the depth value used for volume calculation
• Volume — in US gallons (Imperial mode) or litres with cubic metres (Metric mode). The secondary figure always shows the alternate unit for reference.

Use the Share button to copy a link that preserves your pool outline, depth settings, and map position — useful for sharing with a pool contractor or chemical supplier.

Units: Imperial (US) and Metric (Australia, New Zealand, and International)

The calculator supports both unit systems:

• Imperial: depth in feet, area in square feet, volume in US gallons
• Metric: depth in metres, area in square metres, volume in litres and cubic metres

Switch between systems at any time — all values update instantly. The secondary result always shows the conversion for reference, so an Australian user in Metric mode can still see the US gallon equivalent if needed.

Why Knowing Your Pool Volume Matters

Accurate pool volume is the foundation for almost every aspect of pool maintenance and management:

• Chemical dosing — chlorine, pH adjusters, algaecides, and salt are all dosed per volume. An undersized estimate leads to under-treatment; an oversized one wastes chemicals and can irritate swimmers.
• Salt chlorinator sizing — salt systems are rated for a maximum pool volume. Knowing your exact volume ensures you choose the right unit and set the correct salt target (typically 3,000–4,000 ppm).
• Pool heating — heat pump and gas heater sizing is based on volume and heat-up time requirements.
• Water change calculations — partial or full drains and refills need accurate volume to estimate time, cost, and chemical restart quantities.
• Pool fencing and compliance — in Australia and New Zealand, pool registration and barrier compliance inspections sometimes require documented pool dimensions.

How Pool Volume Is Calculated

The calculator uses the geographic area of the drawn polygon — computed using the Turf.js geospatial library from the actual GPS coordinates on the map — multiplied by the average depth:

Volume = Surface Area × Average Depth

For sloped-bottom pools, average depth is calculated as (shallow depth + deep depth) ÷ 2, which is the standard industry approximation for pools with a consistent linear slope. This method is used by pool professionals and chemical manufacturers worldwide and is accurate to within a few percent for typical residential pool geometries.

Unit conversions used:

• 1 m³ = 1,000 litres
• 1 m³ = 264.172 US gallons
• 1 ft² = 0.0929 m²

Basemap Options

Three satellite and street map basemaps are available via the layer control (top-right of the map):

• ESRI Satellite (default) — high-resolution global imagery from Esri, Maxar, and Earthstar Geographics. Generally the sharpest option for suburban properties.
• Google Satellite — Google Maps satellite imagery, updated frequently for major population centres.
• OpenStreetMap — useful for navigating to an address before switching to satellite view for measurement.

Accuracy and Limitations

This tool is designed for estimation and planning purposes. Accuracy depends on several factors:

• Satellite image resolution — imagery in rural areas or developing regions may be lower resolution, making it harder to trace the pool edge precisely.
• Drawing precision — carefully tracing the pool edge at high zoom levels gives the most accurate area. A rough outline will still give a useful ballpark figure.
• Depth assumptions — the shallow + deep average method assumes a uniform linear slope, which is typical for residential pools. Pools with flat shallow areas, benches, or steps will vary slightly from this estimate.
• Image currency — satellite imagery may be months or years old. This does not affect measurement accuracy but may not reflect recent pool additions or modifications.

For construction, engineering, or regulatory purposes, always verify measurements on-site.

Frequently Asked Questions

How many gallons is a typical backyard pool?

A standard residential pool in the US (approximately 12 ft × 24 ft with an average depth of 5 ft) holds around 10,800 US gallons. In Australia and New Zealand, a common 8 m × 4 m pool at 1.5 m average depth holds approximately 48,000 litres (about 12,700 US gallons). Freeform pools of similar footprint can vary considerably based on shape.

How do I measure an irregular or kidney-shaped pool?

Use the Draw Pool (Freeform) tool and click carefully around the pool edge. The more points you add, the more accurately the shape is captured. Zoom in as far as possible for the best precision.

Can I use this for commercial or public pools?

Yes. The tool works for any pool shape and size. For very large pools (Olympic-sized, wave pools, water parks), zoom out slightly to see the full pool boundary before drawing.

Does the depth of steps and ledges affect the calculation?

The calculator uses the depth values you enter and assumes a uniform or linearly sloped bottom across the full surface area. Tanning ledges, benches, and steps reduce actual volume. For a more conservative estimate, reduce the shallow end depth to account for these features.

What is the difference between US gallons and Imperial gallons?

This calculator uses US gallons (1 US gallon = 3.785 litres). Imperial gallons, used historically in the UK, are larger (1 Imperial gallon = 4.546 litres). Pool chemicals sold in Australia, New Zealand, and the UK are typically dosed by litres, so the Metric mode is most relevant for those regions.

Can I share my pool measurement with someone else?

Yes. After drawing your pool, click the Share button. This copies a URL to your clipboard that encodes the pool outline, depth settings, and map position. Anyone opening the link will see your pool measurement pre-loaded.

About This Tool

This pool volume calculator is built on Leaflet, an open-source JavaScript mapping library, with satellite imagery from Esri and Google. Area calculations use Turf.js, a geospatial analysis library that computes geodesic area from GPS coordinates — accounting for the curvature of the Earth for accurate results at any location worldwide.