Volume of a Conical Frustum (Truncated Cone) Calculator, Formula & Examples

Frustum Volume Formula: V = (1/3) × π × h × (R² + Rr + r²)
Frustum of a Cone Volume Calculator | Auto unit conversion

Frustum of a Cone Volume Calculator | Auto unit conversion

Live calculation updates with unit conversion for each dimension + selectable output cubic units
R r h R r h

📏 Understanding dimensions

  • R = larger radius (top/base)
  • r = smaller radius
  • h = perpendicular height

✔️ Each dimension can have its own unit. Volume result converts to your chosen cubic unit.

supports decimals (e.g., 8.5, 3.2)
comma or point both work
perpendicular height between bases
💡 Each dimension can have its own unit — we convert everything to a common base (meters) before calculating volume.

📊 Instant Results

0.00

🧮 Step‑by‑step calculation

Enter R, r, h and pick units → volume updates instantly.

Volume = (π·h)/3 × (R² + R·r + r²) | internal calculation in meters (m) → result converted to chosen unit.

Table of Contents

What is a Frustum?

A frustum is a geometric shape formed when the top of a cone or pyramid is cut off by a plane parallel to its base. It has two parallel circular bases: one larger and one smaller, and a slanted side surface. Common examples include buckets, cups, and containers.

What is a Conical Frustum?

A conical frustum is simply a cone with its top cut off. Instead of coming to a sharp point, it has two circular ends, a larger base at the bottom and a smaller one at the top. You’ll often see this shape in everyday objects like buckets, paper cups, some funnels, and storage containers. It’s a very practical shape because it is stable, easy to stack, and efficient for holding liquids or materials.

Real-World use cases – why do you need to calculate its volume?

Knowing the volume of a frustum is important when you need to figure out how much something can hold. For example, water tanks, grain silos, industrial containers, and even pipes sometimes use this shape. If you’re in construction, engineering, or even DIY projects, calculating the correct volume helps avoid overfilling or underestimating capacity. It also helps in cost estimation, material planning, and design accuracy.

Cone vs frustum comparison infographic (Truncated Cone) side by side
Difference between Cone and Frustum:
A cone has a pointed top, while a frustum is a cone with the top cut off, resulting in two circular surfaces.

Frustum Cone Volume Formula

The frustum cone volume (also called the truncated cone volume formula) is:

  • V = (1/3) π h (R² + r² + Rr)

This formula helps you quickly find the volume of a shape formed when the top of a cone is cut off. It is widely used in geometry, engineering, and even in everyday tools like a frustum calculator.

What Each Variable Means

R = radius of the bottom (larger circle)
r = radius of the top (smaller circle)
h = vertical height between the two circles
π (pi) ≈ 3.1416

To use the truncated cone volume formula, you simply plug in these values and solve step by step.

Real-World Meaning

This formula is not just for math problems, but it’s used in real life more often than you think. For example, when calculating the capacity of a bucket, water tank, or even a coffee cup, you are actually finding the volume of a conical frustum.

Many industries like construction and manufacturing rely on this formula to estimate material volume and storage capacity. That’s why tools like a frustum volume calculator are so useful that they save time and reduce errors.

How to Calculate Volume of a Frustum

Calculating the volume of a frustum (a cone with its top cut off) is simple when you follow the steps in order. The formula uses the radii of both circular ends and the height of the frustum.

Step-by-Step Calculation

Step 1: Identify the values

  • R = radius of the larger (bottom) circle
  • r = radius of the smaller (top) circle
  • h = height of the frustum

Make sure all values are in the same unit (cm, m, inches, etc.).

Step 2: Square the radii

Now calculate:

  • 𝑅2
  • 𝑟2
  • 𝑅 × 𝑟

These values will be used in the formula.

Step 3: Apply the formula

The formula for the volume of a frustum is:

Frustum Cone Volume Formula

This formula combines the areas of both circles and their interaction.

Step 4: Multiply and divide

  • Add all terms inside brackets
  • Multiply by height ℎ
  • Multiply by π (≈ 3.1416)
  • Finally, divide by 3

This gives the volume of the frustum.

Frustum Cone Volume Formula - step by step calculation
Frustum Volume Formula:
V = (1/3) × π × h × (R² + r² + Rr)

Where: R = base radius
r = top radius
h = height

Example Calculation – Calculate the volume of the frustum

Practice Question:

A frustum-shaped container has:

  • Bottom radius = 6 cm
  • Top radius = 3 cm
  • Height = 10 cm
  1. Calculate the volume of the frustum.
  2. Also express your answer in cubic centimeters (cm³) and liters (L).

This question is asking you to find the space inside a frustum, which is a cone with its top cut off.

To solve this:

  • You are given all three required values: R, r, and h
  • You need to apply the standard frustum volume formula

👉 According to geometry concepts, volume depends on both circular ends and the height, which shows how shapes in space are measured and understood.

Step 1: Square the radii

  • 𝑅2 = 62 = 36
  • 𝑟2 = 32 = 9
  • 𝑅 × 𝑟 = 6 × 3 = 18

Step 2: Add values

36 + 9 + 18 = 63

Step 3: Apply formula

Frustum Cone Volume Formula - example step 3

Step 4: Calculate final value

Frustum Cone Volume Formula step by step example

Final Answer in Multiple Units:

  • 659.73 cubic centimeters (cm³)
  • 0.000659 cubic meters (m³)
  • 0.659 liters (L)

Frustum Volume Conversion Table (mm³ to mL, Liters, Gallons, ft³, in³)

Below is a comprehensive conversion table to help you easily convert frustum volume values from cubic millimeters (mm³) into milliliters (mL), liters (L), US gallons, cubic feet (ft³), and cubic inches (in³).

Volume (mm³) Milliliters (mL) Liters (L) US Gallons Cubic Feet (ft³) Cubic Inches (in³)
10.0010.000001000.000000260.00000003530.00006102
20.0020.000002000.000000530.00000007060.00012205
30.0030.000003000.000000790.00000010590.00018307
40.0040.000004000.000001060.00000014130.00024409
50.0050.000005000.000001320.00000017660.00030512
60.0060.000006000.000001590.00000021190.00036614
70.0070.000007000.000001850.00000024720.00042717
80.0080.000008000.000002110.00000028250.00048819
90.0090.000009000.000002380.00000031780.00054921
100.0100.000010000.000002640.00000035310.00061024
150.0150.000015000.000003960.00000052970.00091536
200.0200.000020000.000005280.00000070630.00122047
250.0250.000025000.000006600.00000088290.00152559
300.0300.000030000.000007930.00000105940.00183071
350.0350.000035000.000009250.00000123600.00213583
400.0400.000040000.000010570.00000141260.00244095
450.0450.000045000.000011890.00000158920.00274607
500.0500.000050000.000013210.00000176570.00305119

This table helps you quickly convert small frustum volumes into practical units used in engineering, construction, fluid measurement, and academic calculations.

Frustum Volume Conversion Table (cm³ to mL, Liters, Gallons, ft³, in³)

Use this conversion table to easily convert frustum volume values from cubic centimeters (cm³) into milliliters (mL), liters (L), US gallons, cubic feet (ft³), and cubic inches (in³) for academic, engineering, and practical applications.

Volume (cm³) Milliliters (mL) Liters (L) US Gallons Cubic Feet (ft³) Cubic Inches (in³)
110.0010.000264170.000035310.0610237
220.0020.000528340.000070630.1220474
330.0030.000792520.000105940.1830711
440.0040.001056690.000141260.2440948
550.0050.001320860.000176570.3051185
660.0060.001585030.000211890.3661422
770.0070.001849200.000247200.4271659
880.0080.002113380.000282520.4881896
990.0090.002377550.000317830.5492133
10100.0100.002641720.000353150.6102370
15150.0150.003962580.000529720.9153555
20200.0200.005283440.000706291.2204740
25250.0250.006604300.000882871.5255925
30300.0300.007925160.001059441.8307110
35350.0350.009246020.001236012.1358295
40400.0400.010566880.001412592.4409480
45450.0450.011887740.001589162.7460665
50500.0500.013208600.001765733.0511850

This table allows quick and accurate conversion of frustum volumes into multiple units, making it ideal for students, engineers, and professionals working with geometric calculations.

Frustum Volume Conversion Table (in³ to mL, Liters, Gallons, ft³)

Below is a detailed conversion table to convert frustum volume values from cubic inches (in³) into milliliters (mL), liters (L), US gallons, and cubic feet (ft³) for accurate and fast calculations.

Volume (in³) Milliliters (mL) Liters (L) US Gallons Cubic Feet (ft³)
116.3870.0163870.0043290.0005787
232.7740.0327740.0086580.0011574
349.1610.0491610.0129870.0017361
465.5480.0655480.0173160.0023148
581.9350.0819350.0216450.0028935
698.3220.0983220.0259740.0034722
7114.7090.1147090.0303030.0040509
8131.0970.1310970.0346320.0046296
9147.4840.1474840.0389610.0052083
10163.8710.1638710.0432900.0057870
15245.8060.2458060.0649350.0086805
20327.7420.3277420.0865800.0115741
25409.6770.4096770.1082250.0144676
30491.6120.4916120.1298700.0173611
35573.5480.5735480.1515150.0202546
40655.4830.6554830.1731600.0231481
45737.4180.7374180.1948050.0260417
50819.3530.8193530.2164500.0289352

This table helps you quickly convert cubic inch values into commonly used volume units, making it ideal for practical applications, education, and technical calculations.

Frustum Volume Conversion Table (ft³ to mL, Liters, Gallons, yd³, m³)

Below is a comprehensive conversion table to convert frustum volume values from cubic feet (ft³) into milliliters (mL), liters (L), US gallons, cubic yards (yd³), and cubic meters (m³).

Volume (ft³) Milliliters (mL) Liters (L) US Gallons Cubic Yards (yd³) Cubic Meters (m³)
128,316.8528.31687.480520.0370370.0283168
256,633.7056.633714.961040.0740740.0566337
384,950.5584.950522.441560.1111110.0849505
4113,267.40113.267429.922080.1481480.1132674
5141,584.25141.584237.402600.1851850.1415842
6169,901.10169.901144.883120.2222220.1699011
7198,217.95198.217952.363640.2592590.1982179
8226,534.80226.534859.844160.2962960.2265348
9254,851.65254.851667.324680.3333330.2548516
10283,168.50283.168574.805200.3703700.2831685
15424,752.75424.7527112.207800.5555560.4247527
20566,337.00566.3369149.610400.7407410.5663369
25707,921.25707.9212187.013000.9259260.7079212
30849,505.50849.5054224.415601.1111110.8495054
35991,089.75991.0896261.818201.2962960.9910896
401,132,674.001,132.6739299.220801.4814811.1326739
451,274,258.251,274.2581336.623401.6666671.2742581
501,415,842.501,415.8423374.026001.8518521.4158423

This table provides fast and accurate conversions of cubic feet into commonly used volume units, helping professionals and students perform efficient and precise calculations.

Frustum Volume Conversion Table (yd³ to mL, Liters, Gallons, ft³, m³)

Below is a detailed conversion table to convert frustum volume values from cubic yards (yd³) into milliliters (mL), liters (L), US gallons, cubic feet (ft³), and cubic meters (m³).

Volume (yd³) Milliliters (mL) Liters (L) US Gallons Cubic Feet (ft³) Cubic Meters (m³)
1764,555764.555201.974270.764555
21,529,1101,529.110403.948541.529110
32,293,6652,293.665605.922812.293665
43,058,2203,058.220807.8961083.058220
53,822,7753,822.7751,009.8701353.822775
64,587,3304,587.3301,211.8441624.587330
75,351,8855,351.8851,413.8181895.351885
86,116,4406,116.4401,615.7922166.116440
96,880,9956,880.9951,817.7662436.880995
107,645,5507,645.5502,019.7402707.645550
1511,468,32511,468.3253,029.61040511.468325
2015,291,10015,291.1004,039.48054015.291100
2519,113,87519,113.8755,049.35067519.113875
3022,936,65022,936.6506,059.22081022.936650
3526,759,42526,759.4257,069.09094526.759425
4030,582,20030,582.2008,078.9601,08030.582200
4534,404,97534,404.9759,088.8301,21534.404975
5038,227,75038,227.75010,098.7001,35038.227750

This table provides quick and accurate conversions for cubic yard volumes into commonly used units, helping professionals and students perform efficient volume calculations.

Frustum Volume Conversion Table (m³ to mL, Liters, Gallons, ft³, yd³)

Below is a comprehensive conversion table to convert frustum volume values from cubic meters (m³) into milliliters (mL), liters (L), US gallons, cubic feet (ft³), and cubic yards (yd³).

Volume (m³) Milliliters (mL) Liters (L) US Gallons Cubic Feet (ft³) Cubic Yards (yd³)
11,000,0001,000264.17235.3151.308
22,000,0002,000528.34470.6292.615
33,000,0003,000792.516105.9443.923
44,000,0004,0001,056.688141.2595.231
55,000,0005,0001,320.860176.5736.539
66,000,0006,0001,585.032211.8887.846
77,000,0007,0001,849.204247.2039.154
88,000,0008,0002,113.376282.51710.462
99,000,0009,0002,377.548317.83211.770
1010,000,00010,0002,641.720353.14713.077
1515,000,00015,0003,962.580529.72019.616
2020,000,00020,0005,283.440706.29426.154
2525,000,00025,0006,604.300882.86732.692
3030,000,00030,0007,925.1601,059.44039.231
3535,000,00035,0009,246.0201,236.01445.769
4040,000,00040,00010,566.8801,412.58752.308
4545,000,00045,00011,887.7401,589.16058.846
5050,000,00050,00013,208.6001,765.73465.385

This table allows quick and accurate conversion of frustum volumes from cubic meters into commonly used units for practical, academic, and industrial applications.

Mega Volume Conversion Chart (US Units)

UnitLiters (L)US GallonsCubic Feet (ft³)Cubic Inches (in³)Milliliters (mL)
1 mm³0.000001 L0.000000264 gal3.53×10⁻⁸ ft³0.000061 in³0.001 mL
1 cm³0.001 L0.000264 gal0.0000353 ft³0.0610 in³1 mL
1 in³0.0164 L0.00433 gal0.0005787 ft³1 in³16.387 mL
1 ft³28.32 L7.48 gal1 ft³1728 in³28,316 mL
1 yd³764.55 L201.97 gal27 ft³46,656 in³764,555 mL
1 m³1000 L264.17 gal35.31 ft³61,023.7 in³1,000,000 mL

Mega Volume Conversion Chart (UK / Imperial Units)

Unit Liters (L) UK Gallons Cubic Feet (ft³) Cubic Inches (in³) Milliliters (mL) UK Fluid Ounces
1 mm³ 0.000001 L 0.00000022 gal 3.53×10⁻⁸ ft³ 0.000061 in³ 0.001 mL 0.000035 fl oz
1 cm³ 0.001 L 0.00022 gal 0.0000353 ft³ 0.0610 in³ 1 mL 0.0352 fl oz
1 in³ 0.0164 L 0.00360 gal 0.0005787 ft³ 1 in³ 16.387 mL 0.577 fl oz
1 ft³ 28.32 L 6.23 gal 1 ft³ 1728 in³ 28,316 mL 996.6 fl oz
1 yd³ 764.55 L 168.18 gal 27 ft³ 46,656 in³ 764,555 mL 26,900 fl oz
1 m³ 1000 L 219.97 gal 35.31 ft³ 61,023.7 in³ 1,000,000 mL 35,195 fl oz

Real life applications of Frustum Volume – Truncated Cone

Construction & Civil Engineering

Frustum calculations are used for structures like tapered columns, bridge piers, water tanks, and foundations. Engineers calculate volume to estimate materials like concrete and cost.

Packaging & Manufacturing

Many containers, such as paper cups, buckets, and food containers have a frustum shape. Manufacturers use volume formulas to determine capacity and optimize material usage.

Chemical & Pharmaceutical Industries

Storage tanks and reactors often have conical or truncated sections. Accurate volume measurement ensures proper mixing, dosing, and safety compliance.

Agriculture & Irrigation Systems

Silos, grain storage bins, and irrigation funnels are often frustum-shaped. Farmers calculate volume to estimate storage capacity and water flow.

Mining & Excavation

When digging pits or trenches with sloped sides, the removed earth forms a frustum shape. Volume calculations help estimate excavation quantities.

3D Modeling & Computer Graphics

Frustum volumes are used in rendering (view frustum) and object modeling for realistic simulations and game development.

Food Industry

Items like cakes, glasses, and molds often resemble frustums. Bakers and chefs use volume calculations for portioning and scaling recipes.

Real life applications of Frustum Volume calculations

Cone Frustum: Volume vs Height Growth (Graph)

The graph showing volume vs height of a frustum cone has an upward-curving shape.
This means the volume increases as the height increases, but not in a simple straight line.

  • At first, when the height (h) is small, the volume increases slowly.
  • As the height grows, the volume starts increasing faster.
  • This creates a curved (non-linear) graph, not a straight line.

Why does this relationship exist?

The main reason comes from the frustum volume formula: V = (1/3)πh(R² + r² + Rr)

  • Volume depends directly on height (h), but also on the radii (R and r).
  • As height increases, the shape becomes “taller,” so more space is added.

But there is more happening:

  • The top and bottom circles stay the same size
  • The side surface stretches, adding more volume layer by layer
  • Each added layer is slightly larger than the one above it

Important Insight

  • As Height ↑ → Volume ↑
  • Growth is curved (non-linear)
  • Larger radii = faster increase in volume

Real-World Graphic Relation

This is why containers like buckets or tanks hold much more liquid when filled higher.
Even a small increase in height near the bottom adds a lot of extra volume.

Cone Frustum vs Height Graph

Cone frustum – Radius vs Volume Growth (Graph)

The graph shows how the volume of a frustum cone changes when the radii (R and r) increase.

The key takeaway is simple: As the radius increases, the volume increases very quickly (not linear relationship).

Why Volume Grows So Fast

The frustum volume formula includes:

  • R² (larger radius squared)
  • r² (smaller radius squared)
  • R × r (interaction term)

Because of these squared terms, even a small increase in radius leads to a much bigger increase in volume.

  • Doubling the radius does not just double the volume
  • It can increase the volume by 3–4 times or more

Understanding the Graph

  • The curve going upward shows accelerated growth
  • The line for R (larger radius) rises faster than r

This means the bottom radius has a bigger impact on volume
The wider the base, the more space the shape can hold

Important Insight

  • Radius ↑ → Volume ↑↑ (faster growth)
  • Larger base (R) affects volume more than smaller base (r)
  • Relationship is non-linear and exponential-like

Real-World Graphic Relation

  • A slightly wider tank holds much more liquid
  • Buckets with larger bases fill faster in terms of volume
  • Industrial containers are designed with wider bottoms

Common Mistakes to avoid when Calculating Frustum Volume

One of the most common mistakes is mixing up radius and diameter. The formula needs the radius, which is half of the diameter. Many people directly use the diameter value, which makes the final answer much larger than it should be. Always double-check your values and divide the diameter by 2 before using it.

Forgetting the Rr Term

The frustum formula has three parts inside the bracket: R² + r² + Rr. A lot of users forget the Rr term (the product of both radii). This small mistake can lead to a big error in volume. Make sure you include all three terms, not just the squares.

Unit Mismatch

Another common issue is using different units for inputs. For example, using height in meters and radius in centimeters will give the wrong result. Always keep all values in the same unit system before calculating.

Always use a frustum calculator with unit conversion to avoid this problem and get accurate results instantly.

Common Mistakes:
  • Using diameter instead of radius
  • Forgetting the Rr term
  • Mixing units (cm vs meters)

Frequently Asked Questions

What is the formula for frustum volume?

The volume of a frustum of a cone is calculated using the formula V = (1/3)πh(R² + r² + Rr), where R is the larger radius, r is the smaller radius, and h is the height.

How do you calculate truncated cone volume?

To calculate truncated cone volume, measure the larger radius (R), smaller radius (r), and height (h), then apply the formula V = (1/3)πh(R² + r² + Rr) and solve step by step.

What is R and r in frustum formula?

In the frustum formula, R represents the radius of the bottom base, while r represents the radius of the top base.

Can frustum volume be negative?

No, frustum volume cannot be negative because volume represents physical space, which is always a positive value.

How to convert frustum volume to liters?

To convert frustum volume to liters, first calculate the volume in cubic meters or cubic centimeters, then use conversion factors such as 1 m³ = 1000 liters or 1 cm³ = 0.001 liters.

What is difference between cone and frustum?

A cone has a single pointed top, while a frustum is formed when the top of a cone is cut off, resulting in two circular faces.

How is frustum formula derived?

The frustum formula is derived by subtracting the volume of a smaller cone from a larger cone, leaving the remaining truncated portion.

What is slant height vs vertical height?

Slant height is the angled distance along the side of the frustum, while vertical height is the straight distance between the top and bottom bases.

Where is frustum used in real life?

Frustums are used in buckets, tanks, chimneys, silos, and packaging designs where a tapered shape is required.

How accurate is frustum calculator?

A frustum calculator is highly accurate when correct input values are used, as it applies a standard mathematical formula.

What happens if r = 0?

If the smaller radius r = 0, the frustum becomes a full cone, and the formula simplifies to the standard cone volume formula.

References

The following trusted academic and educational sources support the formulas, concepts, and real-world applications discussed on this page:

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