Immersed Weight Calculator
Welcome to our immersed weight calculator! If you've ever wondered why objects feel lighter when submerged in water, you'll get your answer here. This immersed weight calculator will help you determine the apparent weight of an object when submerged in any fluid. The calculator has twelve builton fluids, but you can also input any custom fluid you're interested in studying.
When objects are immersed in a fluid, such as water, the object displaces a volume of the fluid. This displaced fluid exerts an upward force on the object, giving the impression that it has become lighter. Keep reading to find out:

What immersed weight is;

How buoyant force affects apparent weight; and

How to calculate the apparent weight of an object immersed in water or any fluid.
What is immersed weight? – Why does weight change when immersed in water?
If you've ever gone swimming, you've probably noticed feeling lighter while in the water. Why is this? Your mass and volume remain the same, but the water exerts an upward force that counteracts the weight of your body. This force is known as the buoyancy or buoyant force, and it's directly proportional to the volume displaced by the submerged object and the density of the fluid.
This is related to Archimedes' principle. Check our Archimedes' principle calculator to read more!
Immersed weight measures an object's weight when it's fully (or partially) submerged in a fluid. We can easily determine it by subtracting the buoyant force from the object's weight (measured outside):
How to calculate the apparent weight – Calculate weight in water
From the previous section, we can see that, for example, if we had an object that weighs $10 \text{ kg}$ outside the fluid, and if once we submerge it displaces $2 \text{ liters}$ of water, then its immersed weight would be of $8 \text{ kg}$. Not sure about this calculation? Let's go stepbystep:
From the previous section, we can see that, for example, if we had an object that weighs $10 \text{ kg}$ outside the fluid and displaces $2 \text{ liters}$ of water once submerged, then its immersed weight would be of $8 \text{ kg}$. Not sure about this calculation? Let's go stepbystep:
1. First, we calculate the object's weight:
where $g$ represents the gravitational acceleration constant of $9.8 \text{ }\mathrm{m/s^2}$ or $32.17 \text{ }\mathrm{ft/s^2}$.
2. Determine buoyancy or buoyant force. For this, we use the following equation:
Where $\rho_{\text{fluid}}$ is the density of the fluid and $V_\text{displaced}$ is the volume displaced by the immersed object. Since we are working with water, then the density of the fluid is $1000 \text{ }\mathrm{kg/m^3}$, and the displaced volume is of $2 \text { l}$ or $0.002 \text{ } \mathrm{m^3}$. By substituting these:
You can find a more indepth explanation of buoyancy and the buoyant force formula at the buoyancy calculator!
3. All that's left is to substitute these values in the initial immersed weight expression:
We see that object's weight went from $98 \text{ N}$ to $78.4 \text{ N}$, or from $10\text{ kg}$ to $8 \text{ kg}$. This example calculates the weight in water, but the same concept can be applied to any other liquid. The main difference would be related to the density of the fluid. Jump to our density calculator to find out what density is and density values for different materials.
How much do I weigh in water?
What would your weight be when fully immersed in water if the average density of a human's body is of $1010 \text{ }\mathrm{kg/m^3}$? Do you float, or do you sink? 🤔
Using the immersed weight calculator to calculate apparent weight
Have you ever wondered what your immersed weight is in water, seawater, or honey? With the immersed weight calculator, you can get the submerged weight of any object in up to twelve different fluids. You can also use this tool to verify the results from immersed weight experiments. Let's a simple stepbystep on how to use this tool:

In the Object properties section, input the
Object volume
and theObject weight
. 
Right away, the calculator will display the Immersed weight of the object in twelve different substances, including water, gasoline, seawater, vegetable oil, and more.
Note that if your result is negative, this indicates that the object floats in that particular fluid. This is the case when the density of the liquid is greater than the object's density.

To find the immersed weight in a fluid not listed, go to the Custom liquid section and enter the
Liquid density
, and the calculator will show theImmersed weight in liquid
andBuoyancy
.
🙋 For immersed weight experiments, you might need to use a ballast to submerge a light object. In that case, indicate the Ballast volume
and the (Ballast + Object) volume
. The calculator will provide the Objects volume
, which you can use for your immersed weight calculations.