Cost Per Gallon Calculator
This calculator determines the price you pay per gallon of a liquid, based on the total cost and the total volume purchased. It's useful for comparing prices of different sizes or brands.
Enter the Total Cost and the Total Volume in Gallons.
Enter Purchase Details
Understanding Cost Per Gallon
What is Cost Per Gallon?
Cost per gallon is a unit price that tells you how much you are paying for each gallon of a product. It standardizes pricing, allowing you to compare the true value of items sold in different sizes (e.g., a quart vs. a gallon) or at different total prices.
Cost Per Gallon Formula
The calculation is straightforward:
Cost Per Gallon = Total Cost / Total Volume (in Gallons)
For example, if you pay $10 for 2 gallons, the cost per gallon is $10 / 2 gallons = $5 per gallon.
Why Use Cost Per Gallon?
- Easy Comparison: Quickly see which size or brand offers the best value.
- Budgeting: Understand the real cost impact of liquids you frequently purchase.
- Informed Decisions: Make smarter choices when shopping, especially for items like gasoline, milk, paint, or cleaning supplies.
Real-Life Cost Per Gallon Examples
Click on an example to see the calculation details:
Example 1: Buying Gasoline
Scenario: You fill up your car, and the pump shows you bought 12 gallons for a total of $42.00.
1. Known Values: Total Cost = $42.00, Total Volume = 12 gallons.
2. Formula: Cost Per Gallon = Total Cost / Total Volume
3. Calculation: Cost Per Gallon = $42.00 / 12 gallons
4. Result: Cost Per Gallon = $3.50/gallon.
Conclusion: The price of gasoline is $3.50 per gallon.
Example 2: Purchasing Milk
Scenario: A gallon of milk costs $3.80.
1. Known Values: Total Cost = $3.80, Total Volume = 1 gallon.
2. Formula: Cost Per Gallon = Total Cost / Total Volume
3. Calculation: Cost Per Gallon = $3.80 / 1 gallon
4. Result: Cost Per Gallon = $3.80/gallon.
Conclusion: The cost per gallon is $3.80.
Example 3: Comparing Juice Sizes
Scenario: You see two options for orange juice: a 1-gallon jug for $4.50 and a half-gallon jug (0.5 gallons) for $2.50.
1. Option A (1 Gallon): Cost Per Gallon = $4.50 / 1 gallon = $4.50/gallon.
2. Option B (0.5 Gallons): Cost Per Gallon = $2.50 / 0.5 gallons = $5.00/gallon.
3. Comparison: $4.50/gallon (Option A) vs. $5.00/gallon (Option B).
Conclusion: The 1-gallon jug is cheaper per gallon.
Example 4: Buying Paint
Scenario: A 5-gallon bucket of paint costs $180.00.
1. Known Values: Total Cost = $180.00, Total Volume = 5 gallons.
2. Formula: Cost Per Gallon = Total Cost / Total Volume
3. Calculation: Cost Per Gallon = $180.00 / 5 gallons
4. Result: Cost Per Gallon = $36.00/gallon.
Conclusion: The paint costs $36.00 per gallon when bought in this size.
Example 5: Purchasing Bulk Liquid Fertilizer
Scenario: A nursery sells liquid fertilizer in bulk. You buy 10 gallons for $75.00.
1. Known Values: Total Cost = $75.00, Total Volume = 10 gallons.
2. Formula: Cost Per Gallon = Total Cost / Total Volume
3. Calculation: Cost Per Gallon = $75.00 / 10 gallons
4. Result: Cost Per Gallon = $7.50/gallon.
Conclusion: The bulk fertilizer costs $7.50 per gallon.
Example 6: Buying Distilled Water
Scenario: You buy a gallon jug of distilled water for $1.20.
1. Known Values: Total Cost = $1.20, Total Volume = 1 gallon.
2. Formula: Cost Per Gallon = Total Cost / Total Volume
3. Calculation: Cost Per Gallon = $1.20 / 1 gallon
4. Result: Cost Per Gallon = $1.20/gallon.
Conclusion: The cost is $1.20 per gallon.
Example 7: Calculating Water Bill Cost (Approx)
Scenario: Your water bill is $60 for the month, and you used 8,000 gallons.
1. Known Values: Total Cost = $60.00, Total Volume = 8,000 gallons.
2. Formula: Cost Per Gallon = Total Cost / Total Volume
3. Calculation: Cost Per Gallon = $60.00 / 8000 gallons
4. Result: Cost Per Gallon = $0.0075/gallon (or 0.75 cents per gallon).
Conclusion: Water from your tap costs very little per gallon.
Example 8: Comparing Cleaning Supplies
Scenario: Brand A cleaner is $15 for 2 gallons. Brand B cleaner is $10 for 1 gallon.
1. Brand A: Cost Per Gallon = $15 / 2 gallons = $7.50/gallon.
2. Brand B: Cost Per Gallon = $10 / 1 gallon = $10.00/gallon.
3. Comparison: $7.50/gallon (Brand A) vs. $10.00/gallon (Brand B).
Conclusion: Brand A is cheaper per gallon.
Example 9: Swimming Pool Chemicals (Approx)
Scenario: You buy 2.5 gallons of pool shock for $30.
1. Known Values: Total Cost = $30.00, Total Volume = 2.5 gallons.
2. Formula: Cost Per Gallon = Total Cost / Total Volume
3. Calculation: Cost Per Gallon = $30.00 / 2.5 gallons
4. Result: Cost Per Gallon = $12.00/gallon.
Conclusion: The pool shock costs $12.00 per gallon.
Example 10: Buying Soda Syrup (Requires Conversion)
Scenario: A bag-in-box soda syrup costs $90 and contains 5 gallons.
1. Known Values: Total Cost = $90.00, Total Volume = 5 gallons.
2. Formula: Cost Per Gallon = Total Cost / Total Volume
3. Calculation: Cost Per Gallon = $90.00 / 5 gallons
4. Result: Cost Per Gallon = $18.00/gallon.
Conclusion: The soda syrup costs $18.00 per gallon.
Units and Conversions
The calculator specifically uses gallons as the volume unit. If your product is sold in other units (like liters, quarts, fluid ounces), you'll need to convert the total volume to gallons before using the calculator. Common conversions:
| Unit | Equivalent in Gallons |
|---|---|
| 1 Quart | 0.25 Gallons |
| 1 Liter | ≈ 0.264172 Gallons |
| 1 Fluid Ounce (US) | ≈ 0.0078125 Gallons |
| 1 Pint | 0.125 Gallons |
Frequently Asked Questions about Cost Per Gallon
1. What is Cost Per Gallon?
It's the price you pay for one U.S. gallon of a liquid product. It's calculated by dividing the total cost by the total volume in gallons.
2. How do I use this calculator?
Enter the total amount you paid in the "Total Cost" field and the total amount of liquid you received, measured in gallons, in the "Total Volume (Gallons)" field. Click "Calculate".
3. What if my product isn't sold in gallons?
You need to convert the volume to gallons first. For example, if you buy 3 quarts, the volume is 3 * 0.25 = 0.75 gallons. If you buy 10 liters, the volume is 10 * 0.264172 ≈ 2.64 gallons. Use online converters if needed, then enter the gallon volume here.
4. Can I compare prices between different units (like a liter bottle vs. a gallon jug)?
Yes, that's exactly what this is for! Just convert the volume of *each* option to gallons first, calculate the cost per gallon for each, and then compare the results.
5. What kind of liquids can I use this for?
Anything sold by liquid volume: gasoline, milk, juice, paint, cleaning supplies, cooking oil, syrups, chemicals, etc., as long as you know the total cost and the total volume.
6. Are there any limitations on the input values?
- Total Cost must be a non-negative number.
- Total Volume must be a positive number (greater than zero), as you can't calculate a per-gallon cost for zero volume.
- Inputs must be valid numbers.
7. Why did I get an error message?
This usually happens if you didn't enter valid numbers, entered negative values, or entered zero for the Total Volume. Make sure both fields contain positive numbers, and Total Volume is not zero.
8. How is this different from Cost Per Liter?
Cost Per Liter calculates the price for one liter, while Cost Per Gallon calculates the price for one gallon. They are both unit prices, but use different volume units. This calculator is specifically for gallons.
9. What does "$/gallon" mean?
It's shorthand for "dollars per gallon", indicating the price for each gallon.
10. Does this calculator account for taxes or fees?
It calculates based on the "Total Cost" you enter. If your "Total Cost" includes taxes and fees, then the resulting "Cost Per Gallon" will also implicitly include them. If you want the pre-tax cost, enter the cost before taxes/fees.
