Inch Feet To Gallon Calculator

Enter feet and inches for each tank dimension. Calculate gallons with shape and fill options. Save accurate reports for project planning and material estimates.

Calculator Form

Use inside measurements for the best estimate. For a cylinder, enter diameter in the length field.

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Example Data Table

Example Shape Dimensions Fill Approx US Gallons
Small tray Rectangular 2 ft × 1 ft 6 in × 10 in 100% 18.70
Garden tank Rectangular 4 ft × 3 ft × 2 ft 75% 134.65
Round storage tank Vertical cylinder 3 ft diameter × 4 ft height 80% 169.23

Formula Used

Feet conversion: total feet = feet + inches ÷ 12

Rectangular volume: cubic feet = length × width × height

Cylinder volume: cubic feet = π × radius² × height

Filled volume: filled cubic feet = full cubic feet × fill percentage ÷ 100

Final gallons: gallons = filled cubic feet × gallon factor × (1 + allowance percentage ÷ 100)

US liquid gallons use 7.48051948 gallons per cubic foot. Imperial gallons use 6.22883546. US dry gallons use 6.428511.

How To Use This Calculator

  1. Select a rectangular tank or vertical cylinder.
  2. Choose the gallon type needed for your report.
  3. Enter feet and inches for each required dimension.
  4. Use internal dimensions for better capacity results.
  5. Add the fill percentage if the tank is partly filled.
  6. Add an allowance if you need extra safety volume.
  7. Press the calculate button to see results above the form.
  8. Download the result as CSV or PDF when needed.

Why This Calculator Helps

An inch feet to gallon calculator helps when dimensions are mixed. Many tank notes use feet for length and inches for depth. Manual conversion can create costly mistakes. This tool combines both units before finding volume. It then converts cubic feet into gallons. You can also apply a fill percentage. That is useful for partial tanks, sumps, liners, troughs, and storage boxes. Label saved reports with the project name, date, and chosen gallon type for future checking.

Better Planning With Gallons

Gallons are easier to use for water, fuel, cleaning solution, coolant, and many liquid estimates. A builder may know the inside length, width, and height. A pond owner may know the filled depth only. A shop owner may need a quick capacity number before ordering supplies. The calculator supports rectangular containers and vertical cylinders. It also gives cubic feet, cubic inches, liters, and water weight estimates.

Accuracy Tips

Always measure internal dimensions. Outside measurements include wall thickness. That extra material changes real capacity. Keep inches below twelve when possible. The calculator still accepts larger inch values. It converts them into feet automatically. For round tanks, enter the diameter in the length field. Enter the height in the height field. The width field is ignored for that shape.

Practical Uses

This page can support home, farm, workshop, and construction tasks. It can estimate a fish tank before filling it. It can size a rectangular cistern. It can check a drain pan. It can compare two container designs. It can also create a quick report using the download buttons. Save the CSV for spreadsheets. Save the PDF for clients, records, or job notes.

Final Notes

The result is an estimate. Real containers may have slopes, rounded corners, fittings, or uneven bases. Liquids may also need safety space at the top. Use the allowance field when extra volume is needed. Use the fill field when the liquid will not reach the full height. Recheck every measurement before buying materials. A small dimension error can change the answer quickly. Repeat the calculation after any design change. Compare full capacity with working capacity. This keeps storage safer and budgets cleaner.

FAQs

What does this calculator convert?

It converts tank or container dimensions given in feet and inches into gallons. It also shows cubic feet, cubic inches, liters, cubic yards, and estimated water weight.

Should I use inside or outside measurements?

Use inside measurements whenever possible. Outside measurements include wall thickness, lips, rims, and framing. Those parts do not hold liquid and can inflate the result.

How do I calculate a round tank?

Select vertical cylinder. Enter the tank diameter in the length field. Enter the tank height in the height field. The width field is ignored for cylinders.

What is the US gallon factor?

One cubic foot equals about 7.48051948 US liquid gallons. The calculator also includes imperial gallons and US dry gallons for different reporting needs.

What does fill percentage mean?

Fill percentage is the usable part of the full volume. Use 100 for a full container. Use 50 for a container filled halfway.

What does allowance percentage do?

Allowance adds extra volume after the fill calculation. It can help with waste, safety margin, spillage, or ordering extra liquid for a project.

Can I save the calculation?

Yes. After calculating, use the CSV button for spreadsheet data. Use the PDF button for a simple report that is easy to store or share.

Why might real capacity differ?

Real containers may have rounded corners, slopes, fittings, uneven bottoms, or thick walls. These details reduce or change actual liquid capacity.

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Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.