# Buoyancy Calculator (Archimedes’ Principle)

URL: https://speedycalculator.com/calculators/physics/buoyancy/
Last updated: 2026-10-25

> The buoyancy calculator finds the upward buoyant force on a submerged object, equal to the weight of fluid displaced, and tells you whether it floats.

## Inputs

- Fluid
- Submerged volume (m³, L, ft³, yd³, US gal)
- Object mass (kg, lb, g, oz, st)

## Results

- Buoyant force
- Object weight
- Net upward force

## Formula

```
F_b = ρ_fluid × V × g
```

## Explanation

Archimedes’ principle explains why ships float and why you feel lighter in water.

### How to use the Buoyancy Calculator

- **Fluid**
- **Submerged volume**
- **Object mass**

Results update as you type, and every field accepts the units shown in its menu.

### How it works

Multiply the fluid density by the submerged volume and gravitational acceleration.

### Inputs explained

FieldWhat to enterFluidChoose one: Fresh water (1,000 kg/m³), Seawater (1,025), Air (1.225), Mercury (13,534)Submerged volumeUnits: m³, L, ft³, yd³, US galObject massUnits: kg, lb, g, oz, st

### What each result means

- **Buoyant force** = [Fluid] × [Submerged volume] × g
- **Object weight** = [Object mass] × g
- **Net upward force** = [Buoyant force] - [Object weight]

### Example values

How the main result changes when **Submerged volume** changes and everything else stays at the example values above:

Submerged volume (m³)Buoyant force (N)0.025245.170.0375367.750.05490.330.0625612.920.075735.50.1980.67

## Worked example

Inputs — Fluid: Fresh water (1,000 kg/m³); Submerged volume: 0.05 m³; Object mass: 40 kg.

Results — **Buoyant force = 490.33 N**; Object weight = 392.27 N; Net upward force = 98.07 N.

## FAQ

**Why do steel ships float?**
Their hollow shape displaces a large volume of water.

**Is it easier to float in the sea?**
Yes, seawater is denser than fresh water.

**What formula does the Buoyancy Calculator use?**
F_b = ρ_fluid × V × g.