How do I determine weight per oz from fluid oz?Updated 25 days ago

How do I determine weight per oz from fluid oz?

1 fluid ounce doesn’t always equal 1 ounce by weight. A fluid ounce measures volume, while an ounce measures weight, and the relationship between the two depends on the product’s density.

Our pricing tool uses fluid ounces simply as a consistent way to estimate ingredient costs, but finished products are often sold by weight, which is the standard for labeling and selling many products.

Also keep in mind that depending on the regulations in your municipality, you may be required to sell products in your refillery by either weight ounces or fluid ounces, so it’s always good to check your local guidelines.

If you ever need to convert between volume and weight for a product, you can do a simple one-time calculation using a graduated cylinder (or other accurate measuring container) and a scale:

1. Fill the cylinder to a known volume line — for example 10 oz by volume.
2. Place it on a scale and record the weight of that amount of product.
3. Divide the weight by the volume to get your multiplier.

For example:

If 10 oz of hand soap by volume weighs 10.1 oz on the scale, your multiplier would be 1.01.

You can then use that multiplier to estimate larger amounts of the same product.

For instance:

• 640 oz (5 gallons) × 1.01 = 646.4 oz by weight

Many refill stores program these multipliers into their counting scales, so once you determine the multiplier once, the scale can automatically calculate the correct weight for any volume your customer wants to purchase.

For reference, here are some approximate weights for 640 oz (5 gallon) containers of common products:

Hand Soap – 689 oz
Dish Soap – 689 oz
Shampoo – 684 oz
Body Wash – 689 oz
Conditioner – 640 oz
Lotion – 640 oz
Vinegar 100 Grain – 680 oz
Vinegar 200 Grain – 684 oz
Fabric Softener – 658.5 oz
Lots of Purpose – 659 oz
Rinse Aid – 661 oz

Please note that these are estimates, and the exact weight can fluctuate slightly from batch to batch. For the most accurate pricing and labeling, we always recommend weighing your finished product.

For pricing help, please refer to our Retail Pricing Tool for calculations and scenarios.