A Gallons Per Square Inch Calculator helps you determine the amount of liquid applied over a specific surface area. This measurement is crucial when you need to know the coverage density of a liquid, such as paint, sealant, or chemical coatings. Instead of guessing, this calculator provides a precise value for how many gallons of liquid are used for every square inch of a surface. This is particularly important in fields like manufacturing, construction, and agriculture, where applying a consistent and accurate layer of a substance is essential for quality and cost-effectiveness. This tool falls under the category of application rate and coverage calculators.
formula
To determine the gallons per square inch, you use a formula that relates the total volume of liquid to the total area it covers.
This formula calculates the volume in gallons applied over a specific area.
Gallons Per Square Inch = Total Gallons of Liquid / Total Area in Square Inches
Component Formulas for Calculating Area
If the total area is not known, you can calculate it using the following formulas based on the shape of the surface. All measurements must be in inches.
For a Rectangular or Square Area
Total Area in Square Inches = Length in Inches * Width in Inches
For a Circular Area
Total Area in Square Inches = 3.14159 * (Radius in Inches)^2
To find the Radius:
Radius in Inches = Diameter in Inches / 2
Application Rate Conversion: From Square Inch to Square Foot
While gallons per square inch (GPSI) is a precise measurement, it can be hard to visualize. Converting this value to gallons per square foot (GPSF) can make it more understandable, as a square foot is a more common unit of area. There are 144 square inches in one square foot.
| Gallons Per Square Inch (GPSI) | Gallons Per Square Foot (GPSF) |
| 0.001 | 0.144 |
| 0.002 | 0.288 |
| 0.005 | 0.720 |
| 0.010 | 1.440 |
| 0.020 | 2.880 |
| 0.030 | 4.320 |
| 0.040 | 5.760 |
| 0.050 | 7.200 |
| 0.100 | 14.400 |
Example
Let's work through an example to see how to calculate gallons per square inch for a real-world task.
Imagine you are applying a waterproof sealant to a circular concrete patio.
First, you need to gather your measurements:
Total Gallons of Liquid: You used 2 gallons of sealant.
Diameter of the circular patio: 10 feet.
Before using the formula, you must convert all measurements to inches.
1 foot = 12 inches
Diameter in Inches = 10 feet * 12 inches/foot = 120 inches.
Next, you calculate the area of the patio in square inches. Since it's a circle, you first find the radius.
Radius in Inches = Diameter in Inches / 2
Radius in Inches = 120 / 2 = 60 inches
Now, calculate the total area.
Total Area in Square Inches = 3.14159 * (60)^2
Total Area in Square Inches = 3.14159 * 3600
Total Area in Square Inches = 11,309.724 square inches
Finally, you can calculate the gallons per square inch.
Gallons Per Square Inch = Total Gallons of Liquid / Total Area in Square Inches
Gallons Per Square Inch = 2 / 11,309.724
Gallons Per Square Inch = 0.0001768
This result shows that a very small amount, approximately 0.000177 gallons of sealant, was applied to each square inch of the patio.
Most Common FAQs
This calculation is vital in any profession where the thickness and consistency of a liquid coating matter. For example, in industrial painting, it ensures that a protective layer meets specifications without wasting expensive materials. In agriculture, it helps in the even distribution of fertilizers or pesticides. It is also used in manufacturing to apply precise amounts of adhesives or lubricants. Essentially, it helps control quality, manage costs, and ensure performance.
It is important not to confuse these two measurements. Gallons per inch measures the volume of a liquid within a three-dimensional container for every one-inch increase in height. It tells you how much liquid is in a tank at a certain depth. In contrast, gallons per square inch measures the amount of liquid spread over a two-dimensional surface area. It tells you about coverage or application thickness, not the volume inside a container.
The formula for gallons per square inch works the same regardless of the liquid being used, whether it's water, paint, epoxy, or oil. The calculation is a pure ratio of volume to area. However, the physical properties of the liquid, such as its thickness or viscosity, will affect how easily you can spread it to achieve a specific coverage rate. A thicker liquid may require more effort or specialized equipment to apply evenly compared to a thinner liquid.