Fluid Ounces to Pounds Conversion
Table of contents
Relation between mass, volume, and densityDefinition of fluid ounces and poundsConverting fluid oz to poundsCalculating pounds to fluid oz conversionUsing this fluid ounces to pounds conversion toolOther related toolsFAQsOur fluid ounces to pounds conversion calculator will help you calculate how many pounds (lbs) a given volume in fluid ounces (fl oz) can weigh using the density of the material. This calculator can handle US fluid ounces and UK fluid ounces!
But isn't an ounce a unit of mass? What are fluid ounces? How can you convert volume into mass? Why is density essential to convert fl oz to pounds? If any of these questions plague you, make sure you go through our following article, where we discuss some fundamentals of this volumetomass conversion, including:
 Mass, volume, and density.
 Definition of fluid ounces and pounds as units.
 Converting fluid oz to pounds.
 Converting lbs to fl oz.
Relation between mass, volume, and density
The density of an object is the ratio of the object's mass to its volume. It is given by:
Where:
 $\rho$  Density of the object;
 $m$  Mass of the object; and
 $V$  Volume of the object.
The SI unit of density is kilograms per cubic meter $\rm{kg/m^3}$.
The above relation is helpful for this volumetomass conversion and vice versa  If we know an object's volume and density, we can determine its mass.
Similarly, if we know the object's mass and density, we can determine its volume.
Definition of fluid ounces and pounds
A fluid ounce (fl oz) is a unit of volume usually used to express the volume of liquids. The Imperial and US Customary systems have different definitions for this unit:

An imperial fluid ounce (UK fl oz or imp fl oz) is defined as ¹⁄₂₀ of an imperial pint or ¹⁄₁₆₀ of an imperial gallon. It is precisely equal to 28.4130625 mL.

A US fluid ounce (US fl oz) is defined as ¹⁄₁₆ of a US pint or ¹⁄₁₂₈ of a US gallon. It is precisely equal to 29.5735295625 mL.
An avoirdupois pound (lbs) is a unit of mass in the Imperial and US Customary system, precisely equal to 0.45359237 kg.
Converting fluid oz to pounds
Now that you know these units, let's learn how to convert fluid oz to lbs:

Convert the density of the material from $\rm{kg/m^3}$ to $\text{lbs/fl oz}$:

Multiply the density with 2.204623, since $1 \text{ kg} = 2.204623 \text{ lbs}$.

For conversion into US fl oz, divide the value obtained in step 1 by 33814, since $1 \text{ m}^3 = 33814\text{ US fl oz}$.

For conversion in UK fl oz, divide the value obtained in step 1 by 35195, since $1 \text{ m}^3 = 35195\text{ UK fl oz}$.


Multiply density in $\text{lbs/fl oz}$ with the volume in US or UK fl oz to get the corresponding mass in pounds.
💡 Need help with density conversion? Try our density conversion calculator now!
Let's understand fluid oz to pounds calculation with an example. Say you have $25 \text{ US fl oz}$ of water, whose density is $1000 \text{ kg/m}^3$. What would be its mass in pounds?

Convert the density into $\rm{lbs/US fl oz}$:

Multiply $1000 \text{ kg/m}^3$ with 2.204623 to get $2204.623 \text{ lbs/m}^3$.

Divide $2204.623 \text{ lbs/m}^3$ by 33814 to get $0.065198\text{ lbs/US fl oz}$.


Multiply $0.065198\text{ lbs/US fl oz}$ with $25 \text{ US fl oz}$ to get the mass in pounds as $1.62995 \approx 1.63 \text{ lbs}$.
Quickly verifying this answer with this fl oz to lbs calculator shows we got the correct answer!
Calculating pounds to fluid oz conversion
Now that you've mastered fluid oz to lbs calculation, let's learn how to perform pounds to fluid ounces conversion:

Similar to fluid oz to pounds conversion, begin by converting the density of the material from $\rm{kg/m^3}$ to $\text{lbs/fl oz}$:

Multiply the density with 2.204623, since $1 \text{ kg} = 2.204623 \text{ lbs}$.

For conversion into US fl oz, divide the value obtained in step 1 by 33814, since $1 \text{ m}^3 = 33814\text{ US fl oz}$.

For conversion in UK fl oz, divide the value obtained in step 1 by 35195, since $1 \text{ m}^3 = 35195\text{ UK fl oz}$.


Divide mass in lbs by the density in $\text{lbs/fl oz}$ to obtain the volume in US or UK fl oz.
Test your understanding of this conversion: Convert $10 \text{ lbs}$ of water whose density is $1000 \text{ kg/m}^3$ into UK fl oz. You can verify your answer with this fl oz to pounds converter!
Using this fluid ounces to pounds conversion tool
Our fluid ounces to pounds conversion tool is simple to use:

Enter the density of the material. You can do this in two ways:
 Select the material from the dropdown lists in the field
Ingredient
, and the calculator will take the corresponding density value in theDensity
field.  Manually enter a custom density value directly in the
Density
field.
 Select the material from the dropdown lists in the field

To convert fl oz to lbs, enter the volume in fl oz in the
Volume
field. Clicking on the unit suffix will open a dropdown list of other units in which you can input your value, including (but not limited to) US fl oz and UK fl oz. 
To calculate lbs to fl oz conversion, enter the mass in lbs in the
Weight/Mass
field. Clicking on the unit suffix will give you more unit options for mass. 
Once you've entered all the required data, your result will automatically appear in the corresponding field!
How many pounds does 15 US fl oz mercury weigh?
15 US fl oz of mercury weighs 13.248 lbs. To calculate this answer manually, follow these steps:
 Look up the density of mercury: 13546 kg/m^{3}.
 Convert the density from kg/m^{3} into lbs/US fl oz:
 Multiply the density with 2.204623 to get: 13546 × 2.204623 = 29,863.823158.
 Divide this value by 33814 to get: 29,863.823158/33814 = 0.883179 lbs/US fl oz.
 Multiply this density by the volume of mercury to get its weight in pounds: 0.883179 lbs/US fl oz × 15 US fl oz = 13.2476 ≈ 13.248 lbs.
Verify your result with our fluid ouncestopounds converter.
How many UK fluid ounces of water is in 22 lbs of water?
22 lbs of water take up 351.2 UK fl oz of volume. To determine this answer yourself, follow these steps:
 Look up the density of water: 1000 kg/m^{3}.
 Convert the density from kg/m^{3} into lbs/US fl oz:
 Multiply the density with 2.204623 to get: 1000 × 2.204623 = 2,204.623.
 Divide this value by 35195 to get: 2,204.623/35195= 0.06264 lbs/UK fl oz.
 Divide the water's mass by this density to get the volume in UK fluid ounces: 22 lbs/0.06264 lbs/UK fl oz ≈ 351.2 UK fl oz.
Verify your result with our fluid ouncestopounds converter.