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Cylinder Density Calculator — Mass, Volume & Density

Enter any two of mass, cylinder dimensions (radius + height), or density and this free cylinder density calculator finds the third. It uses the density of a cylinder formula ρ = m / (πr²h), converts between metric and imperial units, and shows every step of the calculation.

Cylinders only — not cubes. This tool uses V = πr²h. If your object is cube-shaped (one side length, V = s³), use the cube-density calculator (#406) instead; the formulas are not interchangeable.
What do you want to find?

Tip: pick a material below to auto-fill its density, then enter the radius and height.

Density of a Cylinder Formula

ρ = m / V   and   V = πr²h   →   ρ = m / (πr²h)

To calculate the density of a cylinder, divide its mass by its volume, where the cylinder volume is the base area (πr²) times the height. The four rearranged forms cover every case:

Worked example — density of a steel rod: a solid steel cylinder with radius 1 cm, height 10 cm, and mass 246.6 g has volume V = π × 1² × 10 ≈ 31.42 cm³, so ρ = 246.6 / 31.42 ≈ 7.85 g/cm³ — matching the known density of steel.

Common Material Densities

Tap a material to load its density into the calculator, then enter the cylinder's radius and height. Useful for checking whether a gold bar or rod is solid gold vs. plated, estimating shipping weight of metal stock, or verifying a concrete cylinder density test.

MaterialDensity (g/cm³)Density (kg/m³)

How to Find the Density of a Cylinder — Step by Step

  1. Weigh the cylinder to get its mass (a kitchen scale works for small rods and discs).
  2. Measure the diameter with calipers and halve it — this is the radius r. Do not plug the diameter straight into the formula.
  3. Measure the height (or length) of the cylinder.
  4. Compute the volume: V = π × r² × h.
  5. Divide mass by volume: ρ = m / V. Match your units: grams with cm³ gives g/cm³; kilograms with m³ gives kg/m³.
  6. Sanity-check against the table above — if your "gold" cylinder computes to 8.9 g/cm³, it is probably brass or copper.

Cylinder vs. Cube Density — Which Tool Do I Need?

A cylinder density calculator and a cube density calculator answer the same kind of question for different shapes. The volume formulas are completely different: a cylinder uses V = πr²h (needs radius and height), while a cube uses V = s³ (needs a single side length). Using the wrong formula gives a wildly wrong density — a 2 cm cube and a 2 cm-radius cylinder are not comparable volumes at all. Rule of thumb:

Frequently Asked Questions

What is the formula for the density of a cylinder?
ρ = m / (πr²h): mass divided by π times the radius squared times the height.
How do you find the density of a cylinder?
Measure mass, radius and height, compute V = πr²h, then density = mass / volume.
How do you find the mass of a cylinder from density, radius and height?
m = ρ × πr²h. A steel rod (7.85 g/cm³) with r = 1 cm and h = 10 cm weighs 7.85 × 31.42 ≈ 246.6 g.
How do you find the radius of a cylinder from mass, density and height?
r = √(m / (ρπh)). A 246.6 g steel cylinder (7.85 g/cm³), 10 cm tall, has radius 1 cm.
How do you find the height of a cylinder from mass, density and radius?
h = m / (ρπr²). A 62.83 g water cylinder (1 g/cm³) of radius 2 cm is 5 cm tall.
Should I use radius or diameter for cylinder volume?
Radius — V = πr²h. Halve the diameter first; plugging in the diameter directly quadruples the volume.
What is the difference between a cylinder density calculator and a cube density calculator?
Different volume formulas: cylinders use V = πr²h (radius + height), cubes use V = s³ (side). This page (#413) is for round objects; #406 is for cubes. Not interchangeable.
What units are used for cylinder density?
g/cm³, kg/m³, lb/ft³, oz/in³. Note 1 g/cm³ = 1000 kg/m³.
Does the size of a cylinder change its density?
No — density is a material property. A long and short steel rod both measure about 7.85 g/cm³.
How do you calculate the volume of a cylinder?
V = πr²h. A cylinder with radius 2 cm and height 5 cm has volume ≈ 62.83 cm³.
What is the density of a steel cylinder?
About 7.85 g/cm³ (7850 kg/m³); alloys range 7.7–8.0 g/cm³.
What is the density of an aluminum cylinder?
About 2.70 g/cm³ (2700 kg/m³), roughly one-third the density of steel.
Can this calculator find the density of a hollow cylinder or pipe?
No — it assumes a solid cylinder. Hollow pipes use π(R² − r²)h with wall thickness.
How accurate must the radius measurement be?
Very: radius error is squared, so 1% error in r causes ~2% error in density. Use calipers, and halve the diameter.
What is a concrete cylinder density test?
Weighing standard 150×300 mm concrete test cylinders to check density (~2400 kg/m³) and verify mix consistency alongside strength testing.
What is the density of a gold cylinder?
Pure gold is 19.32 g/cm³ — weighing a cylinder and computing ρ = m/(πr²h) is a quick fake check.

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