When it comes to pools, there are many different shapes and sizes to choose from. However, most residential pools tend to follow some general size guidelines. So how big is a standard backyard pool? Let’s take a closer look at some quick answers about standard pool sizes and volumes.
Quick Answer: Average Pool Size
The average volume of a residential swimming pool is around 19,000 gallons or 75,000 litres. This is equivalent to a rectangular pool measuring 15 x 30 feet with an average depth of 4-5 feet.
What is Considered a Standard Pool Size?
While pools come in all shapes and sizes, there are some general standards for typical backyard pools:
- Small: under 15,000 gallons or 56,000 litres. Approximately 12 x 24 feet.
- Medium: 15,000-25,000 gallons or 56,000-95,000 litres. Approximately 15 x 30 feet.
- Large: over 25,000 gallons or 95,000 litres. Often custom designs over 30 feet in length.
The most common pool sizes for residential inground pools are medium-sized rectangles in the 15 x 30 foot range. These provide ample space for swimming laps and recreation without dominating the backyard.
How Many Gallons is a Standard Pool?
As mentioned above, the average residential swimming pool holds about 19,000 gallons of water. This is considered a medium-sized, standard rectangular pool measuring 15 x 30 feet.
Here are some approximations for gallons of water in standard pool sizes:
- 12 x 24 foot pool: around 10,000 gallons
- 15 x 30 foot pool: around 15,000-20,000 gallons
- 20 x 40 foot pool: around 30,000-40,000 gallons
These pool sizes assume an average depth of 4-5 feet. The exact volume will vary based on the pool’s unique shape and dimensions.
How Many Litres are in a 15 x 30 Foot Pool?
For a typical medium-sized 15 x 30 foot rectangular pool, the approximate volume in litres is:
- Length: 15 feet or 4.5 metres
- Width: 30 feet or 9 metres
- Average depth: 4 feet or 1.2 metres
- Volume: Length x Width x Depth
- 4.5 m x 9 m x 1.2 m = 48.6 cubic metres
- 1 cubic metre = 1000 litres
- Total volume = 48,600 litres or 48.6 cubic metres
So a standard 15 x 30 foot backyard pool contains around 48,600 litres or 48.6 cubic metres of water when filled to an average depth of 4 feet.
How Many Litres is a 10 x 20 Foot Pool?
For a smaller 10 x 20 foot rectangular pool, the approximate volume in litres is:
- Length: 10 feet or 3 metres
- Width: 20 feet or 6 metres
- Average depth: 4 feet or 1.2 metres
- Volume: Length x Width x Depth
- 3 m x 6 m x 1.2 m = 21.6 cubic metres
- 1 cubic metre = 1000 litres
- Total volume = 21,600 litres or 21.6 cubic metres
So a smaller 10 x 20 foot backyard pool contains around 21,600 litres or 21.6 cubic metres at an average 4 foot depth.
Standard Pool Sizes in Litres
Here is an overview of typical volumes of common pool sizes in litres:
| Pool Size (Feet) | Approximate Volume (Litres) |
| 12 x 24 | 56,000 |
| 15 x 30 | 48,600 |
| 10 x 20 | 21,600 |
| 20 x 40 | 95,000 |
These volumes are based on an average depth of 4 feet. The exact litre capacity may vary based on unique pool dimensions and depths.
How to Calculate Litres in any Pool Size
You can use the following formula to calculate the approximate volume in litres of any pool:
Volume (litres) = Length (metres) x Width (metres) x Average Depth (metres) x 1000
Simply plug in the measurements of the pool in metres, multiply by 1000 to convert from cubic metres to litres, and you’ll have the total volume.
For example, calculating a 12 x 24 foot pool:
- Length: 12 feet = 3.7 metres
- Width: 24 feet = 7.3 metres
- Average Depth: 4 feet = 1.2 metres
- Volume: 3.7 m x 7.3 m x 1.2 m = 32.5 cubic metres
- 32.5 cubic metres x 1000 litres/cubic metre = 32,500 litres
So a 12 x 24 foot pool contains approximately 32,500 litres when filled to 4 feet deep.
Factors that Affect Pool Volume
When determining the total water volume of a pool in litres, there are several factors to keep in mind:
- Pool Shape – Irregular kidney or oval pools require more complex measurements.
- Depth – The average and maximum depths affect overall volume.
- Features – Steps, benches, swimouts take up space and reduce water volume.
- Slope – Gradual slopes displace more water than vertical walls.
For the most accurate volume, have your pool professionally measured during the design phase. For standard pools, you can make reasonable estimates based on average dimensions and depths.
Volume for Standard Pool Shapes
Rectangular pools are the most straightforward to measure volume. But many backyard pools also come in curved or freeform shapes. Here are some standard shapes and formulas to calculate volumes:
Kidney-Shaped Pools
Kidney pools have a curved organic shape. Calculate as two adjoining half circles with a rectangle in the centre:
- Circle Volume: (πr2)h (r = radius, h = depth)
- Rectangle Volume: Length x Width x Depth
- Total Volume = Circle Volumes + Rectangle Volume
Oval Pools
Oval pools can be calculated as two half ellipses combined with a central rectangle:
- Ellipse Volume ≈ πabh (a = 1/2 length, b = 1/2 width, h = depth)
- Rectangle Volume: Length x Width x Depth
- Total Volume = Ellipse Volumes + Rectangle Volume
Estimating Volume from Pool Surface Area
If you know the surface area of your pool in square metres or square feet, you can also estimate the total volume using the average depth:
- Surface Area x Average Depth = Approximate Volume
While not as accurate as calculating dimensions, it can provide a quick and easy volume estimate.
How Much Does Pool Volume Affect Cost?
In general, larger pool sizes do mean a higher construction cost. However, there are other factors that also greatly impact the overall budget.
- Depth – Deeper pools require more excavation and materials.
- Features – Water features, lighting, tilework add cost.
- Materials – Concrete, fiberglass, vinyl liner options vary in price.
- Labor – Construction complexity and preparation work.
While a larger pool does mean more gallons of water to fill it, the structural work is generally the bigger share of the overall budget. An experienced pool builder can provide accurate quotes for any shape and size of pool.
Typical Costs for Standard Pool Sizes
Here are some typical price ranges for standard sized pools with basic features:
| Pool Size | Cost Range* |
| 12 x 24 feet | $25,000 – $40,000 |
| 15 x 30 feet | $35,000 – $50,000 |
| 20 x 40 feet | $45,000 – $70,000 |
*Costs exclude extras like landscaping, fencing, and accessories.
Keep in mind, custom designs, unique shapes, water features and other upgrades will all increase the final budget. Be sure to get an itemized quote accounting for all your desired amenities.
Maintenance Costs for Standard Pools
Ongoing maintenance is also essential for healthy pool operation. Here are some average annual costs to factor in:
- Chemicals: $150 – $400
- Electricity: $300 – $800
- Upkeep and repairs: $1000 – $2000
- Professional cleaning service: $500 – $2000
Bigger pools may fall on the higher end for chemicals, electricity, and cleaning fees. Proper maintenance from the start helps avoid more costly repairs down the road.
Tips for Choosing the Right Pool Size
When planning your dream pool, keep the following in mind:
- Evaluate your yard size and shape. Allow decking and landscaping space.
- Decide on primary activities – lap swimming, lounging, water features.
- Consider long-term needs – growing family, resell value.
- Consult with designers and builders to narrow plans.
- Compare quotes on materials, features, labor.
- Determine ongoing maintenance costs.
- Leave room in your budget for extras like fencing, cover, heating.
Careful planning ensures you get the right pool for your lifestyle, budget, and backyard. While a larger pool may cost more upfront, it provides greater flexibility and functionality for years to come.
Conclusion
When it comes to residential pools, the standard medium 15 x 30 foot rectangular size contains around 19,000 gallons or 48,600 litres of water. This dimensions allow ample room for exercise and fun within a standard backyard area. Smaller 12 x 24 foot pools start around 10,000 gallons, while larger luxury pools can exceed 40,000 gallons for more customized designs. With proper site planning and design, pool professionals can help tailor the perfect water feature to enhance your landscape and fit your lifestyle needs.
