Fluids Calculators

Fluid mechanics starts with two ratios. Density is mass per unit volume (ρ = m/V), which is what decides whether something floats, and pressure is force spread over an area (P = F/A), which is why a drawing pin pierces a board that your thumb cannot.

Fluids calculators

Pressure

Calculate pressure from force and area (P = F/A).

P = F / A

Density

Calculate density from mass and volume (ρ = m/V).

ρ = m / V

When to reach for these

Use these when the quantity you care about is per-volume or per-area rather than absolute: identifying a material from a weighed sample, or checking whether a load spread over a given footprint is within what a surface can take. Results assume a uniform material and a force applied perpendicular to the area.

Fluids Calculators