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Calculate Gallons in Intex 18×48 Pool: Water Volume Formulas & Measurement Tips (2024)

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How many gallons is my intex 18x48 poolYou’ve just unpacked your new Intex 18×48 pool. Congrats! Now it’s time to fill ‘er up, but how many gallons will it take? Calculating your pool’s volume is crucial for proper pool maintenance. An accurate gallon count lets you add chemicals like chlorine and pH balancers in the right amounts.

Underdosing can lead to algae growth or cloudy water. Overdosing burns your eyes and dries out your skin.

To figure out your pool’s volume, you’ll need to measure the length, width, and average depth. For rectangular Intex pools like yours, it’s easy to calculate. Just multiply the length, width, average depth, and 7.

So for your 18×48 pool, the calculation would be: 18 x 48 x average depth x 7n5. Let’s say your average depth is 48. Then, 18 x 48 x 48 x 7.5 equals 4847 gallons.

Know your gallon amount before filling so you can buy and add chemicals correctly.

Key Takeaways

  • Measure the length, width, and depth of the pool accurately with a tape measure.
  • Use the appropriate formula based on the shape of the pool to calculate the volume in gallons.
  • Keep in mind the importance of knowing the volume for proper chlorine and pH balance.
  • Utilize online calculators and consider factors such as stairs, benches, and sloped sides for precise calculations.

How to Measure Pool Volume

How to Measure Pool Volume
You’d measure its length and width in feet, multiply them together, then multiply by its average depth and by 7.

Determining the right amount of water and chemicals starts with accurately measuring your Intex pool’s dimensions. Use a tape measure to get the length and width at the widest points. For depth, measure from the water’s surface down to the floor, not just the height of the side walls.

An 18 by 48-inch pool holds about 10,000 gallons when filled to 90% capacity. With the measurements, you can use an online pool volume calculator to get a quick and easy gallon amount. Accurate volume helps get the water balance right when adding chlorine, shock, or any other pool chemicals.

Measure carefully and calculate precisely for a safe, sparkling clean Intex pool.

Pool Volume Formulas

Pool Volume Formulas
Calculating the number of gallons your Intex pool holds starts with knowing some key formulas.

For a rectangle pool, you’ll multiply the length, width, and average depth in feet, then multiply by 7.

Round pools use the formula π times the radius squared times depth times 7n5.

Oval pools use a simplified formula of length times width times average depth divided by 231.

If you have an irregular shaped pool, break it into sections, calculate each part separately, then add them together.

Knowing these main volume formulas helps you figure out the water capacity of any shape Intex pool so you can add the right amount of chemicals and equipment.

Rectangle Pool

To compute your rectangular pool’s gallons, multiply the length times width times average depth then by 7n5.

  1. Measure length, width, and average depth in feet.
  2. Multiply the three numbers together.
  3. Multiply the result by 7n5.
  4. This gives you the total gallons.
  5. Use an online calculator for other shapes.

Getting the volume right ensures proper chemical dosing and equipment sizing for your pool.

Round Pool

Here’s the round pool! Measure the diameter and depth to find the volume in gallons. Calculating water capacity ensures proper cleaning equipment size, safe drainage, solar heating, and fencing needs.

Oval Pool

For an oval-shaped pool, you multiply the length by the width by the average depth, then divide by 231 to calculate the gallon capacity. Finding affordable oval liner patches, adding oval pool steps, and cleaning the oval bottom will keep your above-ground pool looking great all season without breaking the bank.

Irregular-Shaped Pool

You’ll have to break that irregularly shaped pool into regular shapes to accurately figure out the gallons, visualizing each section in your mind’s eye. Calculating an irregular pool takes extra work, measuring every dip, slope, and curve.

But with patience, the right tools, and some geometry know-how, you can get a good estimate for filling and treating your custom oasis.

Common Intex Pool Sizes

Common Intex Pool Sizes
Looking for an Intex pool? Popular sizes include the 18×48 inch, holding 4,545 gallons at 90% capacity, the 18×9 inch for smaller yards, the 24×12 inch for medium spaces, and the large 32×16 inch model.

These rectangular pools are affordable options to turn your backyard into a personal oasis.

18×48 Inch

An 18×48-inch Intex pool holds around 4,545 gallons when filled to 90 percent capacity. This size is great for small yards and budgets. Just make sure to use the right chemicals and pump for optimal water quality.

18×9 Inch

You’re splashing in a mini 4,545-gallon backyard oasis.

Advantages Disadvantages
Portable size Less swimming space
Lower cost Can’t install a diving board
Easy setup Limited accessory options
Uses less water Not suitable for laps
Good for small yards Bathing load capacity

Embrace the fun of a portable mini pool. The compact shape and size maximize enjoyment in modest spaces. Scale accessories appropriately for small splashing. The little oasis brings big fun.

24×12 Inch

The 24×12 Intex holds around 3,600 gallons when filled to 90% capacity – perfect for cooling off on a hot day! With a powerful pump and jets, this medium rectangle pool creates a refreshing oasis right in your backyard.

Sturdy fencing provides safety, while the filtration system keeps the water clean and clear.

32×16 Inch

You would have around 2,362 gallons at 90% in your 32×16 Intex pool. Installing water slides, solar heaters, and diving boards opens up fun options.

Estimating Gallons for Intex 18×48 Pool

Estimating Gallons for Intex 18x48 Pool
Dang, an 18×48-inch Intex pool holds around 4,500 gallons at 90% capacity. With that kind of volume, you’ll want to take safety precautions like fencing and alarms. Water depth impacts volume – measure from the surface, not the wall height. Filter size matters too – bigger pools need stronger pumps.

Liner wrinkles are normal with large volumes, just smooth them out. With all that water, chemical concentration is key – test and adjust. When maintained right though, this baby will bring years of safe summer memories.

Tips for Accurate Volume Calculation

Tips for Accurate Volume Calculation
When figuring out your pool’s volume, you’ll want to measure the depth of the water itself, not just the height of the pool walls. An online pool volume calculator makes it much simpler to figure out gallons for unusual shapes like ovals than doing the math yourself.

It’s important to know your pool’s exact volume before adding any chemicals or pumps so you can dose properly. Even with rectangular pools, volume estimates become less precise if there are curved sections or built-in seats.

Start by calculating the cubic feet, then convert to gallons for easy chemical measurement. You’ll need an accurate volume number to maintain safe and effective chlorine, pH, and alkalinity levels.

Measuring Water Depth

You’ll want to measure the depth of the water, not the height of the pool walls, if you want a precise gallon estimate – an 18-foot round pool can hold between 7,646 and 8,602 gallons depending on wall height!

  1. Measure depth in multiple spots
  2. Use a pool depth marker
  3. Average the measurements

To get a precise estimate of your Intex 18×48 pool’s volume, it’s essential to measure the depth of the water rather than just the height of the walls. The water level can vary quite a bit depending on factors like evaporation, rain, and the number of swimmers.

Therefore, checking the depth in several spots and averaging the measurements will give you the most accurate volume calculation.

This extra step is worth it to know you’re adding the right amount of chemicals and equipment for your pool size and shape.

Using Online Calculators

You can quickly get the exact volume by plugging your measurements into an online pool calculator instead of doing the math yourself.

Shape Calculator Tips
Rectangle Calculator 1 Measure length, width, depth
Round Calculator 2 Input radius and depth
Oval Calculator 3 Break into rectangles

Using an online pool volume calculator gives you confidence in chemical dosing for water safety and maintenance.

Importance of Knowing Volume

Knowing your pool’s volume is crucial for proper chemical treatment.

  1. Calculate gallons to add the right chlorine or pH-adjusting chemicals.
  2. Consider water displacement from features like steps and benches.
  3. Factor in wall height for above-ground pools.
  4. Account for covers to estimate evaporation.

Precise volume calculation allows correct chemical dosing. Too little chlorine won’t sanitize, and too much can damage your pool and equipment.

For custom measurements, use an online calculator for accuracy. Break irregular shapes into rectangles or circles. Measure length, width, and depth in feet to determine gallons. Calculate wall height separately for above-ground pools.

Volume dictates circulation equipment size and runtimes. Proper turnover rates keep chemicals dispersed, and right-sized pumps and filters improve efficiency.

Take time to correctly measure and calculate. Proper chemical balance and clean, safe water depend on it.

Accuracy for Unusual Shapes

Dividing your tarp-walled lagoon into rectangles, triangles, and circles will help pinpoint each segment’s capacity before totaling them up. For maximum accuracy, factor in sloped sides, curved walls, and the depth of the deep end into your calculations.

Calculating Cubic Feet First

Calculating cubic feet before gallons gets your volume calculation off to a precise start, partner.

  • Measure pool length, width, and depth in feet.
  • Multiply for cubic feet.
  • Convert cubic feet to gallons.

Getting the cubic feet first avoids rounding errors and ensures your final gallon estimate is as accurate as can be for planning chemicals and equipment.

Chemical Dosing Considerations

You’ll need the volume for proper chemical amounts. Knowing the pool’s gallons allows you to add the right sanitizer and balancing chemicals for water safety and efficiency.

Pool Volume Calculator

Pool Volume Calculator
To figure out the volume of your Intex 18×48 pool, simply enter the measurements into an online calculator. Make sure to input the pool’s length, width, and average depth in feet. Then, select the shape of your pool, whether it’s a rectangle, oval, round, or any other shape.

After entering the measurements, you will receive the volume of your pool in gallons. It’s always a good idea to double-check the accuracy of the calculation by manually calculating the volume as well.

Save the result for future reference, as it will come in handy when determining the amount of chemicals, filters, and heating required for your pool. Having an accurate volume measurement will also help you choose the right equipment, such as filters, pumps, and heaters, for your pool.

So, don’t rely on guesswork and let the calculator do the math for you. This way, you can sit back, relax, and enjoy crystal clear water all season long.

With an accurate gallon amount, you can properly size and dose pool chemicals, determine pumping and heating requirements, and ensure safety by managing water usage. Precise volume helps match your pool with the right filter, pump, heater, and other equipment too.

Don’t guess – let the calculator do the math, so you can relax and enjoy crystal clear water all season long.

Pool Volume Reference Chart

Pool Volume Reference Chart
Per the reference chart, an Intex 18×48 pool holds approximately 4,545 gallons at 90% capacity. This is a good mid-sized above ground pool for most backyards. When installing your 18×48 pool, be sure to level the ground and provide proper support around the pool walls.

An appropriately sized pump and filter will keep your water clean and safe – aim for turnover every 6-8 hours.

Here’s a quick reference for common Intex pool sizes:

Pool Size Gallons at 90%
12 ft Round 3,000
15 ft Round 5,000
18 ft Round 8,000
18×48 in 4,545
24×12 in 5,500

When using pool chemicals or installing equipment like heaters or cleaners, knowing your pool’s volume is key for proper dosing and pump sizing.

Step-by-Step Guide to Calculate Pool Volume

Step-by-Step Guide to Calculate Pool Volume
Figuring out your pool’s gallons the right way is crucial for proper chemical maintenance. To determine the volume of a basic rectangular pool, simply measure the length, width, and average depth in feet, then multiply those numbers together and by 75.

For a more accurate read on an irregularly shaped pool, divide it into separate rectangles and triangles to calculate each section’s volume, then add them all together.

Pool Volume Calculation Basics

Measuring your pool’s length, width, and average depth in feet and then multiplying them gives its volume in gallons. To obtain the most accurate measurement, use a tape measure and dipstick to determine the pool’s dimensions and depth when it is full.

If necessary, break the shape into rectangles or circles. Multiply the length by the width and then by the average depth in feet, and finally, multiply the result by 7.5 to convert it to gallons. This basic method works for any pool shape. For irregular pools, calculate the sections separately.

Using correct measurements ensures the proper amount of chemicals when treating your pool.

Calculating Rectangular Pool Volume

You’ll wow your guests when you know your beloved backyard oasis holds over 10,000 gallons!

To find the volume of your rectangular pool:

  • Measure length, width, and average depth in feet
  • Plug measurements into the formula: L x W x D x 7.5
  • Adjust for partial fills or unique shapes
  • Use volume markers to confirm the calculation
  • Online calculators handle irregular sizes

Knowing your pool’s volume helps get chemical dosing right.

Constant Depth

Constant Depth
Feel the satisfaction as you swiftly multiply the length, width, and depth to get the volume in gallons of your beloved Intex pool. An 18×48-inch Intex pool has dimensions of 18 feet long, 4 feet wide, and an average depth of 4 feet.

Simply multiply 18 x 4 x 4 to get 288 cubic feet. Then multiply 288 cubic feet by 7.

The result is 2,160 gallons for an 18×48-inch Intex pool at full capacity. With this precise volume measurement, you can confidently add the proper chemical dosages and filtration to keep your pool water clean, clear, and safe all season long.

Length (ft) Width (ft) Depth (ft)
18 4 4

Variable Depths With a Gradual Slope

Variable Depths With a Gradual Slope
When calculating volumes for gradually sloped pools, we gotta break out them calculators ‘n get creative, friend.

  • Measure the shallow and deep ends to find the slope.
  • Estimate volume at different depths along the slope.
  • Remember slope impacts the shape too.

Getting an accurate gallon count requires taking multiple measurements at different points. Don’t forget to account for stairs or benches either, those tricky shapes throw off the math. With some slope savvy and calculator calibration, we can nail down a reliable volume for partial or full filling.

Variable Depths With a Drop-Off

Variable Depths With a Drop-Off
When tackling an irregularly shaped pool, you’ve got some calculations ahead of you. Start by dividing the pool into manageable shapes like rectangles, squares, and circles. Measure the length, width, and average depth for each section in feet. Now you can plug those numbers into the formulas for a rectangular prism or cylinder to get the volume in cubic feet.

Once you’ve totaled the cubic footage of each section, multiply by 7.5 to convert to gallons. Round pools are easier since you only need the radius and average depth. With a little bit of geometry know-how, you’ll have your pool’s volume figured out in no time.

Calculating Round or Circular Pool Volume

Figuring out the gallons in your round pool is not an easy task. The first step is to measure the radius and then find the diameter in order to calculate the circumference. Next, you need to obtain the surface area by multiplying the diameter by itself and pi.

Lastly, the volume is equal to the area multiplied by the average depth. Cylinder formulas make the calculations easier once you have the measurements. Round pools require more mathematical calculations, but we will guide you through the process.

Calculating Irregular-Shaped Pool Volume

You’ll need to divide your Intex 18×48 pool into sections in order to calculate the total volume if it has variable depths or drop-offs. Divide the pool into squares, rectangles, circles, and triangles. Measure the dimensions of each section.

Calculate the volume of each shape separately by multiplying length, width, and depth. Add all the volumes together for a close approximation of your pool’s full capacity. With some geometry, you can obtain a good estimate for even the most irregularly shaped pools.

When to Seek Professional Help for Pool Measurement

When to Seek Professional Help for Pool Measurement
Round up a pro rapidly if you reckon the reservoir’s rough. We know calculating gallons seems straightforward, but odd shapes or slopes can throw off your figuring. Professional land surveyors have the tools and know-how to map your pool precisely.

They check drainage, electrical hazards, construction codes – all the nitty-gritty permit requirements. DIY methods work for simple setups, but complex pools need expert measuring. Getting an accurate assessment from the get-go prevents headaches down the line.

Save yourself time, trouble, and money: call in the pros when in doubt about your pool’s gallons.

Frequently Asked Questions (FAQs)

What if my Intex pool is not a perfect rectangle?

If your Intex pool isn’t a perfect rectangle, don’t panic. You can still calculate the volume accurately. Break the pool into sections, measure each one separately, then add them together. Use the formulas for rectangles, squares, and circles that fit each section’s shape.

It takes a little more work, but it’s worth it to know you’re adding the right amount of chemicals.

How often should I recalculate the volume as water evaporates over time?

It’s best to recalculate your pool’s volume every couple of weeks during peak swim season when evaporation is highest. Simply remeasure the length, width, and water depth and plug the new numbers into a pool volume calculator.

This ensures you don’t overdose chemicals. Make recalculating part of your routine maintenance.

Can I use the same formulas for above-ground vs in-ground pools?

Yes, you can use the same formulas for both above-ground and in-ground pools. The shape and dimensions determine the volume, not whether it’s in or above the ground. Just be sure to measure the water depth, not the pool wall height, for the depth value when calculating.

How accurate do my measurements need to be?

When measuring your pool, accuracy matters! Get as precise as you can with a tape measure for length and width. Depth is trickier – use multiple measurements for an average. Volume estimates work with a 1-2 inch variance.

What tools can I use to measure my pool if I don’t have a tape measure?

You can get creative using household items to measure your pool if you lack a tape measure. Use a yardstick, rope, string, even cans or shoes lined up end-to-end. For the radius, tie a string to a pole and walk in a circle.

Or trace the outline on paper and measure that. Just be as precise as possible for an accurate gallon estimate.


You’ve got this! Measuring your Intex 18×48 pool doesn’t have to be complicated. Just grab a tape measure, jot down the length, width, and average depth in feet, then plug it all into an online pool volume calculator.

In a flash, you’ll know exactly how many gallons your pool needs to stay happy and healthy all season long. Trust me, taking a few minutes upfront to get the right volume will save you big time and money on chemicals down the road.

Avatar for Mutasim Sweileh

Mutasim Sweileh

Mutasim is an author and software engineer from the United States, I and a group of experts made this blog with the aim of answering all the unanswered questions to help as many people as possible.