Gallons to Cubic Yards Converter
Instantly convert US gallons to cubic yards, cubic feet, liters, cubic meters, imperial gallons, and more — with live precision control, quick presets for common tank & cistern sizes, composite yd³ & gal display, and a downloadable PDF report.
Assumes US gallons: 1 US gal = 231 in³ and 1 yd³ = 46,656 in³, so 1 yd³ = 201.974 gal. Imperial gallons shown separately — for reference only.
| US gallons | Cubic yards | Cubic feet | yd³ & gal |
|---|
Gallons to Cubic Yards Conversion — Complete Guide for 2026
Converting US gallons to cubic yards (yd³) bridges the gap between liquid volumes and bulk-material volumes. Pools, ponds, septic tanks, cisterns, and hot tubs are rated in gallons, while the soil dug out to install them, the fill used to close them, and the concrete, gravel, and topsoil around them are sold by the cubic yard. The key relationship is exact: 1 cubic yard = 201.974 US gallons, so 1 US gallon ≈ 0.00495113 yd³.
Our free Gallons to Cubic Yards Converter takes a volume in US gallons and returns cubic yards at 0 to 8 decimal places, splits the result into whole cubic yards plus leftover gallons (500 gal becomes 2 yd³ 96.05 gal), and converts across the volume ladder — cubic feet, liters, cubic meters, cubic inches, and imperial gallons. Quick presets, a log-scale comparison chart, a common-tank reference table, and a downloadable PDF report make it useful for a quick check or for excavation, fill, and project paperwork.
How to Use the Gallons to Cubic Yards Converter in 4 Steps
A complete gallons-to-cubic-yards conversion takes a few seconds. Enter a volume or tap a preset, choose your precision, and download a PDF report you can attach to an excavation quote, fill order, or project file.
Enter Your Volume in US Gallons
Type any volume in US gallons — a tank rating, a pool or pond volume, or a spa capacity. The calculator handles everything from a 50-gallon rain barrel to a large pool with the same exact math, and updates on every keystroke.
Or Tap a Quick Preset
Common tank and cistern sizes are one tap away: 100, 250, 500, 1,000, 2,000, and 5,000 gallons. Each chip shows its cubic-yard value, so you can read the answer before you click. The active preset stays highlighted, and typing a matching value re-selects it automatically.
Set Decimal Precision
Use the input or slider to pick 0 to 8 decimal places for the cubic-yard result (the default is 5). Two decimals suit fill, soil, and excavation orders; four or more suit plans and technical records. Cubic feet, liters, and other units use fixed, sensible precision.
Review & Download PDF
See your volume in cubic yards, cubic feet, yd³-and-gallons, US gallons, liters, cubic meters, cubic inches, and imperial gallons, plus a chart comparing the numbers. Click Download PDF for a two-page branded report with every conversion, the chart, and a highlighted reference table.
Why 1 Cubic Yard = 201.974 Gallons
The US gallon comes from the old English wine gallon and is defined as exactly 231 cubic inches (3.785411784 liters). The cubic yard is a cube 1 yard — 36 inches — on each side, so it contains 36 × 36 × 36 = 46,656 cubic inches, or 27 cubic feet. Dividing one by the other gives 46,656 ÷ 231 = 201.974025974… gallons per cubic yard.
Because both units are defined in cubic inches, the conversion is exact — but the result is a repeating decimal, so neither direction gives a round number. That’s why rough shortcuts like “200 gallons per yard” creep into estimates. The calculator uses the exact 231/46,656 ratio internally, so there is no rounding drift. For metric equivalents, 1 cubic yard is exactly 0.764554857984 m³ — see our Cubic Yards to Cubic Meters Converter.
Liquid volume vs bulk-material volume
A cubic yard is the same size whether it holds water or gravel, but the two behave very differently in practice:
- Water — 1 yd³ = 201.974 gallons, weighing about 1,684 lb (about 8.34 lb per gallon). The volume is the volume.
- Excavated soil — swells when dug, so a hole of 1 yd³ produces more than 1 yd³ of loose dirt to haul away.
- Fill material — compacts when placed, so filling 1 yd³ of space usually takes more than 1 yd³ of delivered fill.
On a 20,000-gallon pool, rounding to 200 gallons per yard adds about 1 yd³, but ignoring compaction or swell can change the answer by 20 yd³ or more. Because the conversion itself is exact, the real uncertainty comes from the tank or pool volume you start with and how the material behaves once it’s moved.
What the Gallons to Cubic Yards Converter Calculates
More than a single cubic-yard figure — the tool gives you a complete volume breakdown across US customary, metric, and imperial units, formatted for tanks, pools, excavation, fill orders, or reports.
Exact Cubic Yards (Hero Result)
The headline result multiplies your gallons by the exact ratio 231/46,656 and shows it at the precision you select, with a summary line beneath it that also gives cubic feet and the cubic-yards-and-gallons split.
Cubic Feet
Cubic feet (gal × 0.133681) are how bagged soil, mulch, and gravel are sold and how many tank dimensions are specified. One cubic foot holds about 7.48 gallons, so small volumes are easier to read in ft³.
Cubic Yards & Gallons (Composite)
The result is split into whole cubic yards plus leftover gallons — 500 gal becomes 2 yd³ 96.05 gal. That shows at a glance how close a tank or pool is to the next whole yard of fill or excavation.
Liters & Cubic Meters
Liters (gal × 3.785411784) and cubic meters (L ÷ 1,000) match metric tank ratings, international product sheets, and engineering documents, so you can compare a US tank with a metric one directly.
Cubic Inches & Imperial Gallons
Cubic inches (gal × 231) cover small containers and exact definitions, and imperial gallons (L ÷ 4.54609) cover older UK and Canadian tank specifications, which use a gallon about 20% larger.
Chart, Reference Table & PDF
A log-scale bar chart compares your value in gallons, cubic yards, cubic feet, liters, and cubic meters so very different magnitudes fit on one view. A reference table of common tank sizes highlights your input when it matches, and the two-page PDF bundles everything for sharing or record-keeping.
Gallons to Cubic Yards Conversion Chart — Common Values
Bookmark this page or screenshot the table below for instant reference. Every value uses the exact definitions 1 US gallon = 231 in³ and 1 yd³ = 46,656 in³, rounded to four decimals for cubic yards and two for cubic feet and liters. Tank, spa, and pool examples are typical sizes that vary by product and design.
| US Gallons | Cubic Yards | Cubic Feet | Liters | Common Use |
|---|---|---|---|---|
| 50 gal | 0.2476 yd³ | 6.68 ft³ | 189.27 L | Rain barrel (typical) |
| 100 gal | 0.4951 yd³ | 13.37 ft³ | 378.54 L | Stock tank or large aquarium |
| 201.97 gal | 1.0000 yd³ | 27.00 ft³ | 764.55 L | Exactly 1 cubic yard |
| 250 gal | 1.2378 yd³ | 33.42 ft³ | 946.35 L | Small water tank or cistern |
| 400 gal | 1.9805 yd³ | 53.47 ft³ | 1,514.16 L | Hot tub or spa (typical) |
| 500 gal | 2.4756 yd³ | 66.84 ft³ | 1,892.71 L | Above-ground water tank |
| 750 gal | 3.7133 yd³ | 100.26 ft³ | 2,839.06 L | Small septic tank |
| 1,000 gal | 4.9511 yd³ | 133.68 ft³ | 3,785.41 L | Common septic tank or cistern |
| 1,500 gal | 7.4267 yd³ | 200.52 ft³ | 5,678.12 L | Larger septic tank or cistern |
| 2,000 gal | 9.9023 yd³ | 267.36 ft³ | 7,570.82 L | Large cistern |
| 5,000 gal | 24.7557 yd³ | 668.40 ft³ | 18,927.06 L | Backyard pond or plunge pool |
| 10,000 gal | 49.5113 yd³ | 1,336.81 ft³ | 37,854.12 L | Small in-ground pool |
| 20,000 gal | 99.0226 yd³ | 2,673.61 ft³ | 75,708.24 L | Average in-ground pool (typical) |
How to Use Gallons and Cubic Yards for Pools, Tanks, and Fill
The most common reasons people convert gallons to cubic yards are to estimate fill for closing a pool, soil to haul when digging a pond or tank hole, and the size and weight of water storage. Each one needs the unit conversion — and an allowance for how soil and fill behave once they’re moved.
The manual calculation
Step 1: Find the volume in US gallons from the pool, tank, or pond specification. Step 2: Divide by 201.974 to get cubic yards. Step 3: Add an allowance for compaction (fill) or swell (excavation). For filling in an old 20,000-gallon pool:
99.02 yd³ × 1.20 (example 20% compaction allowance) = 118.83 yd³
Result: plan on roughly 119 yd³ of fill — confirm with your contractor
Enter the gallon figure into the calculator and it does the first two steps for you: the hero result shows cubic yards, the cubic-feet line helps with smaller volumes, and the “yd³ & gal” card shows how far past the last whole yard you are. The right allowance depends on the material and how it’s compacted, so treat the example percentage as a placeholder, not a rule.
Water weight and storage
When water is stored above ground, on a deck, or inside a building, weight matters as much as volume:
- Weight — water is about 8.34 lb per gallon, so 1 yd³ (201.974 gal) weighs about 1,684 lb.
- Hot tubs — a 400-gallon spa holds about 1.98 yd³ of water, or about 3,336 lb before the tub and people are added.
- Rainwater — 1 inch of rain on 1,000 sq ft of roof is about 623 gallons, or about 3.09 yd³.
- Filling time — minutes to fill = gallons ÷ flow rate in GPM; use our GPM to LPM Converter for metric flow rates.
Gallons to Cubic Yards — Key Conversion Numbers
The Gallons to Cubic Yards Converter Is Built For You If…
Whether you’re filling in an old pool, digging a pond, or sizing a rainwater cistern — this calculator gives you the exact answer in seconds, with a report you can save and share.
Homeowners & Homebuyers
Pools, septic & cisternsSeptic tanks, pools, and cisterns are described in gallons, while the dirt, fill, and gravel around them are priced by the cubic yard. Converting helps you understand a property’s systems, estimate the scale of a pool removal, and make sense of contractor quotes.
- A 1,000-gallon septic tank is about 4.95 yd³
- A 20,000-gallon pool is about 99 yd³ before allowances
- Ask whether pool removal needs permits or compaction tests
- Keep the PDF with inspection or project records
Excavation, Landscape & Pool Contractors
Digging, hauling & fillContractors move between customer volumes in gallons and material quantities in cubic yards. Converting quickly — then adding the right swell or compaction allowance — keeps excavation, hauling, and fill quotes accurate and easy for clients to follow.
- yd³ = gal ÷ 201.974 for in-place volume
- Add swell for hauling, compaction for fill
- Show both gallons and yards on quotes
- Attach the PDF to show the factor used
Rainwater, Pond & Spa Owners
Storage, weight & spaceRain barrels, cisterns, ponds, and hot tubs are sold by the gallon, but the space they take, the hole they need, and the weight they put on a deck or slab are easier to judge in cubic feet, cubic yards, and pounds.
- 1 inch of rain on 1,000 sq ft ≈ 623 gal
- Water weighs about 8.34 lb per gallon
- A 400-gal spa holds about 3,336 lb of water
- Have deck or slab capacity checked by a pro
7 Tips for Accurate Gallons to Cubic Yards Conversions
The conversion is exact, but the volumes and materials around it often aren’t. Most mistakes come from mixing gallon types, ignoring swell and compaction, trusting nominal tank sizes, and rounding too early. These rules keep every conversion trustworthy.
Confirm US or Imperial Gallons
A cubic yard is 201.974 US gallons but only 168.18 imperial gallons. US tanks and pools use US gallons; check older UK or Canadian specifications before converting.
Allow for Swell and Compaction
Dug soil swells, so hauling needs more than the hole’s volume; fill compacts, so filling a space needs more than its volume. Convert first, then add the allowance your contractor recommends for the material.
Nominal vs Working Capacity
A tank’s rated gallons may differ from its usable volume because of headspace, inlet and outlet levels, or rounding. Use the manufacturer’s actual capacity when the number matters.
Don’t Round to 200
Dividing by 200 instead of 201.974 overstates cubic yards by about 1%. That’s small for a spa, but on a large pool it adds about a cubic yard. Use the calculator for orders and quotes.
The Hole Is Bigger Than the Tank
Excavation for a tank, cistern, or pool includes wall thickness, bedding, and working room. The liquid volume in cubic yards is a minimum, not the dig volume — ask for the installer’s excavation dimensions.
Remember the Weight
Water is heavy: about 8.34 lb per gallon and about 1,684 lb per cubic yard. Convert gallons to weight before placing tanks or spas on decks, roofs, or upper floors, and have the structure checked.
Memorize Three Anchors for Mental Math
1 yd³ ≈ 202 gal. 1 ft³ ≈ 7.5 gal. 1,000 gal ≈ 5 yd³. With these you can sanity-check any quote in your head — a 5,000-gallon pond is about 25 yd³, and a 10-yard load of fill is about 2,020 gallons of space.
Gallons to Cubic Yards Converter — Frequently Asked Questions
Everything you need to know about converting gallons to cubic yards, how liquid volumes compare with soil and fill, and how to apply this calculator to pools, ponds, septic tanks, cisterns, and hot tubs.
One US gallon equals about 0.00495113 cubic yards. The figure is exact because a US gallon is defined as 231 cubic inches and a cubic yard is 36 × 36 × 36 = 46,656 cubic inches, so 1 gallon = 231 ÷ 46,656 cubic yards. Put the other way, 1 cubic yard holds about 201.974 US gallons.
Divide US gallons by 201.974: yd³ = gal ÷ 201.974, which is the same as yd³ = gal × 0.00495113. For example, 500 gal = 2.4756 yd³, 1,000 gal = 4.9511 yd³, and 10,000 gal = 49.5113 yd³. To go from cubic yards back to gallons, multiply by 201.974.
One cubic yard holds about 201.974 US gallons (exactly 46,656 ÷ 231). For example: 1 yd³ = 201.97 gal, 5 yd³ = 1,009.87 gal, 10 yd³ = 2,019.74 gal, and 50 yd³ = 10,098.70 gal. This converter takes gallons as its input; to check a result, enter the gallon figure you calculated and confirm the cubic-yard result matches.
One cubic foot holds about 7.48052 US gallons (exactly 1,728 ÷ 231), or about 28.32 liters. Since a cubic yard is 27 cubic feet, 27 × 7.48052 = 201.974 gallons per cubic yard. One gallon is about 0.13368 cubic feet.
Start by converting the pool’s water volume to cubic yards: a 20,000-gallon pool holds about 99 cubic yards. Contractors usually order extra fill because soil settles as it is compacted, so the actual amount can be noticeably higher. Pool removal is often regulated and may need permits, engineered fill, or compaction testing, so get a contractor’s estimate before ordering.
Convert the planned water volume to cubic yards to get the in-place soil volume, then allow for swell — excavated soil loosens and takes up more space, often around 20% to 30% more depending on soil type. A 5,000-gallon pond is about 24.76 cubic yards in place, or roughly 30 to 32 cubic yards of loose soil to haul away.
Water weighs about 8.34 pounds per US gallon, so a cubic yard of water (201.974 gallons) weighs about 1,684 pounds, or roughly 0.84 US tons. In metric terms, a cubic meter of water weighs about 1,000 kg. The exact weight varies slightly with temperature.
A US gallon is 3.785411784 liters, while an imperial (UK) gallon is 4.54609 liters — about 20% larger. So a cubic yard holds about 201.974 US gallons but only about 168.18 imperial gallons. US tanks and pools are rated in US gallons; check older UK or Canadian specifications before converting.
A typical 400-gallon hot tub holds about 1.98 cubic yards of water, which weighs about 3,336 pounds at 8.34 lb per gallon. Add the tub itself and the people using it, and the total load can be far higher. Have a qualified professional confirm that a deck or slab can support it before installation.
One inch of rain on 1,000 square feet of roof is about 623 US gallons, or about 3.09 cubic yards. Actual collection is lower because of gutter overflow, evaporation, and first-flush diverters, so size cisterns and rain barrels with some margin.
A 1,000-gallon septic tank holds about 4.95 cubic yards (133.68 cubic feet), and a 1,500-gallon tank holds about 7.43 cubic yards (200.52 cubic feet). The excavation needed is larger than the tank’s liquid capacity because of wall thickness, bedding, and working space, and required tank size is set by local health codes.
The converter uses exact definitions: 1 US gallon = 231 in³ = 3.785411784 L; 1 cubic yard = 46,656 in³ = 27 ft³; 1 ft³ = 1,728 in³; and 1 imperial gallon = 4.54609 L. Calculations use double-precision floating-point arithmetic, accurate to about 15 significant digits, and display precision is adjustable from 0 to 8 decimal places. In practice, accuracy is limited by the tank rating or measurement you start with, not by the conversion.
Accuracy note: The HomeExpertly Gallons to Cubic Yards Converter uses the exact definitions 1 US gallon = 231 cubic inches = 3.785411784 liters and 1 cubic yard = 46,656 cubic inches = 27 cubic feet, so 1 cubic yard = 201.974 US gallons, together with 1 imperial gallon = 4.54609 liters, based on the inch as defined by the 1959 International Yard and Pound Agreement and recognized by the U.S. National Institute of Standards and Technology (NIST). All calculations are mathematically precise to the decimal precision you select (up to 8 places). However, results are for informational and reference purposes only. Tank ratings may differ from usable capacity, excavated soil swells and fill compacts, and water weight varies slightly with temperature. Tank, spa, pool, compaction, swell, and rainfall examples on this page are typical or illustrative figures that vary by product, soil, climate, and site. For applications where volume or weight is critical — including but not limited to pool removal, excavation and fill orders, septic system sizing, structural loading of decks and slabs, stormwater or rainwater systems, or contract pricing — always verify figures independently using manufacturer specifications, site measurements, applicable permits and codes, and a licensed contractor, engineer, or other qualified professional. HomeExpertly is not responsible for any consequences arising from the use of these conversions, including but not limited to material shortages or overages, settlement, structural damage, code violations, or pricing disputes.