Pool Water Volume Calculator (2026): Gallons + Chemical Dosing Guide
Calculate your pool's water volume in gallons instantly β works for rectangle, oval, kidney, round, and L-shape pools. Includes:
- Auto-conversion to gallons, liters, cubic feet, cubic meters
- Live chemical dosing β chlorine shock, salt, stabilizer, pH adjusters, calcium chloride
- Refill cost estimator using JEA Jacksonville water rate ($0.0066/gallon)
- Typical pools: 14Γ28Γ5 ft = 14,653 gal Β· 16Γ32Γ5 ft = 19,149 gal Β· 18Γ36Γ5 ft = 24,235 gal
- Formula: Rectangle = L Γ W Γ avg depth Γ 7.48 (gallons per cubic foot)
Accurate within Β±3-10% by shape
Updated May 2026
Live chemical dosing reference
No email required
Free Pool Water Volume Calculator
Pick your shape, enter dimensions β get gallons + chemical doses instantly.
Pool shape
Rectangle
Oval
Round
Kidney / Freeform
L-Shape
Dimensions
Depth
Avg depth: 5.0 ft Β· For uniform depth, enter same value in both fields
Your pool volume
14,653
gallons (US)
55,469
Liters
1,960
Cubic feet
55.5
Cubic meters
12,206
Imperial gallons
Refill cost: $97 at JEA Jacksonville rate ($0.0066/gallon). Fill time: 24β48 hours via garden hose.
Live chemical dosing for your pool volume
Doses calculated automatically based on your pool size from the calculator above. All recommendations use standard formulas β verify with test kit before adding chemicals.
Critical chemistry safety rules: (1) Always test water BEFORE adding chemicals; (2) Never mix different chemicals directly β add separately with 4+ hours between; (3) Add chlorine/acid at dusk to prevent UV degradation and reduce fumes; (4) Always dissolve granular chemicals in a bucket of water first before adding to pool; (5) Wear gloves and eye protection when handling muriatic acid or chlorine; (6) Wait 24 hours after shock or major chemical addition before swimming.
Typical pool volumes by size (gallons)
Quick reference for common pool sizes. All values for rectangular pools with 5 ft average depth β adjust for your actual avg depth.
| Pool size (L Γ W) | Surface area | 4 ft avg | 5 ft avg | 6 ft avg |
|---|---|---|---|---|
| 10 Γ 20 (small) | 200 sq ft | 5,983 gal | 7,479 gal | 8,975 gal |
| 12 Γ 24 (compact) | 288 sq ft | 8,615 gal | 10,766 gal | 12,919 gal |
| 14 Γ 28 (standard) | 392 sq ft | 11,723 gal | 14,653 gal | 17,584 gal |
| 16 Γ 32 (mid-large) | 512 sq ft | 15,319 gal | 19,149 gal | 22,979 gal |
| 18 Γ 36 (large) | 648 sq ft | 19,388 gal | 24,235 gal | 29,082 gal |
| 20 Γ 40 (extra large) | 800 sq ft | 23,936 gal | 29,920 gal | 35,904 gal |
Formula: L Γ W Γ avg depth Γ 7.48 = gallons. For non-rectangular pools, use the calculator above with shape-specific formulas.
Pool volume formulas by shape
All formulas use feet for dimensions and return gallons. Multiplier of 7.48 converts cubic feet to gallons.
| Pool shape | Formula | Accuracy |
|---|---|---|
| Rectangle | L Γ W Γ avg depth Γ 7.48 | Β±1β2% |
| Round | Ο Γ radiusΒ² Γ avg depth Γ 7.48 | Β±2β5% |
| Oval | Ο Γ (L/2) Γ (W/2) Γ avg depth Γ 7.48 | Β±2β5% |
| Kidney / freeform | 0.45 Γ L Γ W Γ avg depth Γ 7.48 | Β±5β10% |
| L-shape | Sum of two rectangles | Β±2β5% |
| Irregular | Divide into sections, sum each | Β±5β15% |
Average depth for variable-depth pools: (shallow + deep) Γ· 2 (assumes linear slope). For hopper pools (sudden drop), use weighted average based on area of each depth zone.
Pool water volume & chemical dosing: 30 FAQs (2026)
Everything pool owners ask about calculating volume and dosing chemicals. Click any question to expand.
Volume basics
1. How do I calculate my pool's water volume?
Pool water volume in gallons = Length Γ Width Γ Average Depth Γ 7.48 (for rectangular pools). For other shapes: Round = Ο Γ radiusΒ² Γ avg depth Γ 7.48; Oval = Ο Γ (L/2) Γ (W/2) Γ avg depth Γ 7.48; Kidney/freeform = 0.45 Γ L Γ W Γ avg depth Γ 7.48; L-shape = sum of two rectangles. Average depth = (shallow + deep) Γ· 2 for linear-slope pools. Multiply by 7.48 because there are 7.48 gallons per cubic foot of water. Typical inground pool = 13,000β35,000 gallons. A 14Γ28Γ5 ft pool = 14,653 gallons.
2. How many gallons of water are in a typical inground pool?
A typical inground pool holds 13,000β35,000 gallons. Average sizes: small (10Γ20Γ4) = 5,983 gal; compact (12Γ24Γ4.5) = 9,693 gal; standard (14Γ28Γ5) = 14,653 gal; mid-large (16Γ32Γ5) = 19,149 gal; large (18Γ36Γ5) = 24,235 gal; extra large (20Γ40Γ5) = 29,920 gal. Most Florida inground pools fall in the 12,000β22,000 gallon range. Knowing your volume is critical for accurate chemical dosing, equipment sizing, and refill cost estimation.
3. How many gallons is a 14Γ28 pool?
A 14Γ28 ft rectangular pool with 5 ft average depth holds 14,653 gallons. Variations by depth: 14Γ28Γ4 ft = 11,723 gal; 14Γ28Γ4.5 ft = 13,188 gal; 14Γ28Γ5 ft = 14,653 gal (most common); 14Γ28Γ5.5 ft = 16,118 gal; 14Γ28Γ6 ft = 17,584 gal. For variable depth (3 ft shallow, 6 ft deep = 4.5 ft avg): 13,188 gallons. The 14Γ28 is the most common Florida inground pool size β about 28% of new builds. For dosing: 1.5 lbs of pool shock, 290 lbs of salt for new saltwater conversion, 30 lbs of stabilizer for 30 ppm initial dose.
4. How many gallons is a 16Γ32 pool?
A 16Γ32 ft rectangular pool with 5 ft average depth holds 19,149 gallons. Variations by depth: 16Γ32Γ4 ft = 15,319 gal; 16Γ32Γ4.5 ft = 17,234 gal; 16Γ32Γ5 ft = 19,149 gal; 16Γ32Γ5.5 ft = 21,064 gal; 16Γ32Γ6 ft = 22,979 gal. For diving end (3.5 shallow, 8 ft deep = 5.75 ft avg): 22,022 gallons. The 16Γ32 is the most popular family-upgrade size, with 22% of new Florida builds. For dosing: 2 lbs of pool shock per dose, 380 lbs of salt for new saltwater conversion, 40 lbs of stabilizer for 30 ppm.
5. What's the formula for pool volume?
Pool volume formulas by shape (result in gallons): Rectangular pool: L Γ W Γ avg depth Γ 7.48. Round pool: 3.14159 Γ radiusΒ² Γ avg depth Γ 7.48 (radius = diameter Γ· 2). Oval pool: 3.14159 Γ (length Γ· 2) Γ (width Γ· 2) Γ avg depth Γ 7.48. Kidney or freeform pool: 0.45 Γ longest length Γ widest width Γ avg depth Γ 7.48. L-shaped pool: calculate each rectangular section separately and sum. Average depth for variable-depth pools: (shallow + deep) Γ· 2. The 7.48 multiplier converts cubic feet to gallons (1 cubic foot = 7.48052 gallons).
6. How much does it cost to fill a pool?
Filling a typical 14Γ28 inground pool (14,653 gallons) from garden hose: $97β$135 in Jacksonville at JEA's $0.0066/gallon residential rate, taking 18β36 hours via standard 5/8-inch hose at 5β10 GPM. Faster options: (1) Trucked-in water β $200β$400 per 6,000-gallon truck, total $500β$1,000; (2) Fire hydrant connection (requires permit) β saves time but minimal cost savings; (3) Multiple garden hoses simultaneously β fills in 6β12 hours. New pool first-fill startup chemistry adds $100β$300. Florida law requires backflow protection during refill.
Chemical dosing
7. How much chlorine do I add to my pool?
Chlorine dosing depends on pool volume and form: Chlorine tablets (trichlor 90%): 1 tablet per 10,000 gallons in floater or skimmer. Liquid chlorine (sodium hypochlorite 10%): 0.5 gallon per 10,000 gallons raises free chlorine by 5 ppm. Granular chlorine (cal hypo 65%): 0.5 lb per 10,000 gallons raises free chlorine by 5 ppm. Pool shock: 1 lb per 10,000 gallons. Target free chlorine: 1β3 ppm. NEVER mix different chlorine types directly β can cause explosion. For a typical 14Γ28 pool (14,653 gallons): 1.5 lbs of shock per dose, 0.75 lbs of granular chlorine to raise 5 ppm.
8. How much shock do I need for my pool?
Pool shock dose: 1 lb of cal hypo shock (65% calcium hypochlorite) per 10,000 gallons for a standard shock treatment, raising free chlorine by 10β12 ppm. Quick reference: 5,000 gal = 0.5 lbs; 10,000 gal = 1 lb; 15,000 gal = 1.5 lbs (typical 14Γ28); 20,000 gal = 2 lbs (typical 16Γ32); 25,000 gal = 2.5 lbs; 30,000 gal = 3 lbs. Double the dose for algae bloom or post-storm shock. Shock when: chlorine reads below 1 ppm, after heavy rain, after pool party, weekly during peak summer. Add at dusk so UV doesn't break it down. Wait 24 hours before swimming after shock.
9. How much stabilizer (cyanuric acid) does my pool need?
Stabilizer (cyanuric acid, CYA) dose: 0.13 lbs per 10,000 gallons raises CYA by 1 ppm. Target: 30β50 ppm for chlorine pools (extends chlorine life 3β5Γ in sun); 50β80 ppm for saltwater pools. For a 14Γ28 pool (14,653 gallons) starting from 0: 4 lbs raises CYA to 20 ppm; 6 lbs raises to 30 ppm; 10 lbs raises to 50 ppm. Add through skimmer with pump running. CYA does NOT degrade naturally β only diluted by adding fresh water or partial drain. If CYA gets above 100 ppm ('chlorine lock'), partial drain is the only fix. Trichlor tablets ARE stabilized chlorine β long-term tablet use raises CYA automatically.
10. How much salt does a saltwater pool need?
Saltwater pool salt dose: target 3,000β4,500 ppm (most salt cells specify 3,200 ppm). To convert freshwater to saltwater: add 26.4 lbs of pool-grade salt per 1,000 gallons to reach 3,200 ppm. Quick reference: 10,000 gal = 264 lbs; 14,000 gal (typical 14Γ28) = 370 lbs; 16,000 gal = 422 lbs; 20,000 gal (typical 16Γ32) = 528 lbs; 25,000 gal = 660 lbs. Salt comes in 40 lb bags ($8β$15 each) β typical conversion cost $75β$300. Add slowly through skimmer with pump running over 1β2 days. Annual top-off: 50β80 lbs per year for typical pool.
11. How much baking soda does my pool need?
Baking soda (sodium bicarbonate) raises alkalinity. Dose: 1.5 lbs per 10,000 gallons raises total alkalinity by 10 ppm. Target alkalinity: 80β120 ppm. For a 14Γ28 pool (14,653 gallons) raising alkalinity from 60 to 100 ppm: 8.8 lbs of baking soda. Use ACTUAL baking soda from grocery store ($1β$2/lb) β same chemical as 'pool alkalinity up' products sold at 3β5Γ the price. Add slowly through skimmer with pump running. Baking soda raises pH slightly β if pH is already high, use sodium carbonate (soda ash) instead. Low alkalinity causes pH swings and corrosion; high alkalinity causes cloudy water and scale.
12. How do I lower pH in my pool?
Lower pH using muriatic acid (hydrochloric acid 31.45%) or dry acid (sodium bisulfate). Muriatic acid dose: 8 fl oz per 10,000 gallons lowers pH by 0.2. For a 14Γ28 pool (14,653 gallons) lowering pH from 8.0 to 7.6: 24 fl oz (about 0.75 cups) muriatic acid. Target pH: 7.4β7.6. NEVER add acid to water of unknown chemistry. Add slowly to deep end with pump running. Wear gloves and eye protection β muriatic acid causes severe burns and toxic fumes. Wait 4β6 hours before retesting. High pH (above 7.8) causes scale, cloudy water, and reduces chlorine effectiveness 50%+.
13. How do I raise pH in my pool?
Raise pH using sodium carbonate (soda ash) or aeration. Soda ash dose: 6 oz per 10,000 gallons raises pH by 0.2. For a 14Γ28 pool (14,653 gallons) raising pH from 7.0 to 7.6: 27 oz (about 1.7 lbs) soda ash. Target pH: 7.4β7.6. Add slowly through skimmer with pump running. Soda ash raises alkalinity slightly. Alternative: aeration (run water features, splash) physically raises pH by releasing dissolved CO2 β free but slower. For low alkalinity AND low pH, use baking soda. For low pH but normal alkalinity, use soda ash. Low pH (below 7.2) causes corrosion, etching, and rapid chlorine consumption.
14. How much calcium chloride does my pool need?
Calcium chloride raises calcium hardness. Dose: 1.5 lbs per 10,000 gallons raises calcium hardness by 10 ppm. Target: 200β400 ppm for plaster pools; 150β250 ppm for vinyl liner pools. JEA water (Jacksonville) is calcium-soft at 100β220 ppm β most pools need ongoing calcium additions. For a 14Γ28 pool (14,653 gallons) raising calcium from 150 to 250 ppm: 22 lbs of calcium chloride. Add to bucket of warm water first (exothermic β generates heat), then pour into skimmer. Low calcium causes etching of plaster (water 'eats' calcium, accelerating wear). NE Florida homeowners should test calcium hardness monthly β extends plaster life 2β5 years.
Pool shapes
15. How do I calculate pool volume for a kidney-shaped pool?
Kidney or freeform pool volume formula: 0.45 Γ longest length Γ widest width Γ avg depth Γ 7.48. The 0.45 multiplier approximates the curved shape. Example: kidney pool 30 ft long Γ 18 ft wide Γ 5 ft avg = 0.45 Γ 30 Γ 18 Γ 5 Γ 7.48 = 9,083 gallons. Some kidney pools use 0.40β0.50 depending on curve aggressiveness β narrow waist with wide ends use 0.40; gentle kidney use 0.50. For most pools, 0.45 is accurate within Β±5%. For high-precision, use the dye-dilution test (add known dose of test chemical, measure concentration change, back-calculate volume) β accurate within 1β2%.
16. How do I calculate volume for a round pool?
Round pool formula: Ο Γ radiusΒ² Γ avg depth Γ 7.48. Where Ο = 3.14159 and radius = diameter Γ· 2. Example: 24 ft diameter round pool, 4 ft avg depth = 3.14159 Γ 12Β² Γ 4 Γ 7.48 = 13,538 gallons. Quick reference (4 ft avg depth): 15 ft diameter = 5,287 gal; 18 ft = 7,613 gal; 21 ft = 10,365 gal; 24 ft = 13,538 gal (typical large above-ground); 27 ft = 17,135 gal; 30 ft = 21,154 gal. Most above-ground round pools are 4 ft deep uniform. Hot tubs use different formulas (truncated cone) β manufacturer specs usually list gallons directly.
17. How do I calculate volume for an oval pool?
Oval pool formula: Ο Γ (length Γ· 2) Γ (width Γ· 2) Γ avg depth Γ 7.48. Treats oval as a stretched circle. Example: oval pool 30 ft Γ 15 ft Γ 4 ft avg = 3.14159 Γ 15 Γ 7.5 Γ 4 Γ 7.48 = 10,572 gallons. Quick reference (4 ft avg depth): 12Γ24 ft = 6,773 gal; 15Γ30 ft = 10,572 gal; 18Γ33 ft = 13,977 gal; 18Γ36 ft = 15,240 gal (typical above-ground oval). The Ο factor approximates true volume within Β±2% for most oval shapes.
18. How do I calculate volume for an irregular pool?
Three methods for irregular pools: (1) Section method: divide pool into rectangular and circular sections, calculate each separately, sum results. Example L-shape: section 1 (14Γ20) + section 2 (10Γ14) = sum. (2) Rope perimeter method: lay rope around pool edge, measure rope length, use rectangular approximation (0.4 Γ L Γ W if shape varies dramatically). (3) Dye-dilution method (most precise): add known weight of liquid chlorine, measure resulting free chlorine concentration, back-calculate volume. For most freeform/irregular pools, the 0.45 multiplier formula is accurate within Β±10%. For precise dosing, professional volume measurement costs $50β$150.
19. What if my pool has different depths (shallow and deep end)?
Use average depth: avg depth = (shallow depth + deep depth) Γ· 2. This works for pools with linear bottom slope. Example: 14Γ28 pool with shallow 3 ft and deep 7 ft = avg depth 5 ft. For 'hopper' pools (flat shallow, sudden drop), use weighted average based on area of each section. Example: 14Γ28 pool with 70% at 4 ft + 30% at 8 ft = (0.7 Γ 4) + (0.3 Γ 8) = 5.2 ft avg depth. For pools with multiple distinct depths, divide into sections and calculate each volume separately. Most residential pools use linear slope and (shallow + deep) Γ· 2 is accurate within Β±3%.
Refill & water cost
20. How long does it take to fill a pool?
Standard 5/8-inch garden hose flows 5β10 GPM, filling at: 14,000 gal pool in 23β47 hours; 20,000 gal in 33β67 hours; 30,000 gal in 50β100 hours. Two hoses cut time in half. Trucked-in water: 6,000-gallon truck unloads in 20β45 minutes β 2 trucks fill typical 14Γ28 pool in 1β2 hours. Fire hydrant (with permit and meter rental): 50β100 GPM, fills 14,000 gal in 2β5 hours. JEA hydrant rental: $50 setup + $150 meter deposit. Most homeowners use 2 garden hoses for new fills (12β24 hours) and 1 hose for top-offs.
21. How much does it cost to fill a pool from a fire hydrant?
Fire hydrant water rental in Jacksonville costs $250β$400 for a typical 14Γ28 pool fill. Components: hydrant meter deposit $150 (refunded), permit and setup $50β$100, water at JEA rate $0.0066/gallon = $97 for 14,653 gallons, hose rental $25β$50/day. Time advantage: fills in 2β5 hours vs. 18β48 hours via garden hose. Permit process: apply through JEA, takes 3β7 business days. Not always faster than running 2 garden hoses overnight. Trucked-in water is usually easier for new pool fills: 2 trucks Γ $300 = $600, 1β2 hours total.
22. Can I use a hose to fill my pool?
Yes β standard garden hose is the most common pool fill method. Use 5/8-inch or 3/4-inch hose at 5β10 GPM. Total cost for typical 14Γ28 pool (14,653 gallons) at JEA $0.0066/gallon: $97. Time: 24β48 hours via single hose, 12β24 hours via two hoses. CRITICAL: Florida code requires backflow protection at the hose bib during pool fill β prevents pool chemicals from siphoning back into your home's drinking water. Most home improvement stores sell $5β$15 backflow preventers. NEVER leave unattended fill on chemical-treated pool β float a valve or use a timer.
23. How much does pool water cost per gallon?
Pool water cost per gallon by source in 2026: JEA Jacksonville municipal water $0.0066/gallon ($6.60 per 1,000 gallons); FPL/Tampa Electric service areas $0.0050β$0.0080/gallon; California municipal $0.0080β$0.0150/gallon; trucked-in water $0.03β$0.07/gallon; well water $0 per gallon (but adds pump electricity). Total fill cost for typical 14Γ28 pool (14,653 gallons): JEA $97; trucked-in $450β$1,000; well water $5β$15. Pool fills don't go to sewer β call your water utility before filling and request a sewer-fee credit for the pool fill volume. JEA typically grants this on request, saving $100β$300.
24. Should I use trucked-in water vs garden hose?
Trucked-in is 5β10Γ more expensive per gallon but fills in 1β2 hours vs. 24β48 hours. Use trucked-in when: (1) Filling for the first time on a new pool (need to start chemistry quickly to prevent plaster damage); (2) After major resurfacing or repair when timing matters; (3) Your water utility has restrictions on filling. Use garden hose when: (1) Routine top-off; (2) Cost matters more than time; (3) You can monitor the fill. Most NE Florida homeowners use garden hose for everything except new pool fills (where trucked is usually worth the extra $400β$800 for speed).
Accuracy & methods
25. How accurate are pool volume calculators?
Pool volume calculators are accurate within Β±3β10% depending on shape. Rectangular uniform depth: Β±1β2%. Rectangular with shallow/deep ends: Β±2β4%. Round and oval: Β±2β5%. Kidney/freeform: Β±5β10%. L-shape and irregular: Β±5β15%. For chemical dosing, Β±5% accuracy is sufficient β adding 1.5 lbs vs. 1.4 lbs of shock makes no real difference. For precise applications (saltwater conversion), use dye-dilution method which gives Β±1% accuracy. Calculator inaccuracy is rarely the issue β measurement error (eyeballing depth, mis-estimating shape) typically dominates the final accuracy.
26. How do pool service companies measure volume?
Pool service companies use 4 methods: (1) Builder specs β most accurate, pulls from original construction plans; (2) Shape-formula calculation β measures L, W, depth at multiple points, uses same formulas as DIY calculators; (3) Dye-dilution test β most precise (Β±1%), adds known weight of liquid chlorine, measures resulting concentration change with electronic test meter; (4) Flow meter at fill β install meter on fill hose, record total gallons added. Most service companies use method 2 for new customer estimates ($0 extra) and offer method 3 as paid add-on ($50β$150) when precise chemistry matters.
27. Why does my pool service company's volume estimate differ from mine?
Differences typically come from: (1) Depth measurement variation β pros measure depth at 4β8 points and average; DIY usually measures 2 points; (2) Shape estimation β pros use digital pool-shape tools; DIY uses approximate formulas; (3) Wall slope accounting β pools with sharply sloped walls have less water than surface measurement suggests; (4) Pool plaster thickness β pros sometimes subtract for thick pebble finishes; (5) Equipment volume β pros sometimes subtract plumbing volume. Typical difference: 5β15%. Both are 'right' enough for chemical dosing. If difference is over 20%, one measured something wrong β redo with tape measure.
Practical applications
28. Why do I need to know my pool volume?
Pool volume is the foundation calculation for nearly every pool decision. Critical uses: (1) Chemical dosing β chlorine, salt, stabilizer all dose per 10,000 gallons; getting volume wrong by 30% means over/under-dosing by 30%; (2) Equipment sizing β pump GPM, filter capacity, heater BTU all size based on volume; (3) Heater operating cost β heating cost scales linearly with volume; (4) Salt cell sizing β salt cells rated for max gallons; (5) Water replacement costs after a drain; (6) Refill water cost estimation; (7) Initial fill chemistry budget; (8) Insurance damage claims. Most pool owners only learn their volume when they first need to dose chemicals β by then over-dosing is common. Calculate once, write down, save for life.
29. How does pool volume affect my pump sizing?
Pool pump sizing rule: pump should turn over total pool volume 1β1.5 times per day. Calculation: required pump GPM = pool gallons Γ· (60 min Γ 8 hr) for 8-hr daily runtime. Example sizing: 14,000 gal pool needs 29 GPM (about 1 HP variable-speed pump); 20,000 gal needs 42 GPM (1.5 HP VS pump); 25,000 gal needs 52 GPM (1.5β2 HP VS pump); 30,000 gal needs 63 GPM (2 HP VS pump). Florida code (FBC 2020) requires variable-speed pumps on all new pools. Oversized pumps waste energy; undersized pumps can't keep water clear. Most builders default to 1.5 HP VS pump for pools up to 25,000 gallons.
30. How does pool volume affect heating cost?
Heating cost scales linearly with pool volume. BTU to raise 1Β°F = pool gallons Γ 8.34 lbs/gal Γ 1Β°F. For typical 14Γ28 pool (14,653 gal): BTU to raise 1Β°F = 122,210 BTU. To raise from 70Β°F to 82Β°F (12Β°F rise): 1,466,500 BTU = about 15 therms of natural gas at 85% efficiency = $24 at JEA $1.35/therm. OR 84 kWh of heat pump electricity at COP 5 = $12 at JEA $0.143/kWh. To maintain at 82Β°F overnight in 60Β°F outside: depends on wind/cover but typically 10β30% of initial heat needed. Use our Pool Heater ROI Calculator for full sizing.
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