Cubic Inch Calculator

Q: Why did my quantity and waste allowance stop counting?

That happens when you type a number straight into the Total Volume box. The tool switches to manual mode and just converts the number you typed. Quantity and waste are skipped. To turn auto mode back on, change any size in the shape section above, or click Clear / Reset .

Q: Can I use this for a half sphere or dome?

Yes. Pick Sphere , type the radius, then cut the answer in half. A half sphere is exactly 50% of a full sphere. Quick trick: set Quantity to 0.5 and the tool halves it for you.

Q: For a cone, do I use the slant height or the straight height?

Use the straight height. Measure from the middle of the base straight up to the tip, not along the slanted side. The slant side is always longer, so using it makes your volume too big.

Q: Is cc the same as a cubic centimeter?

Yes. cc and cm³ mean the same thing. Pick cm³ / cc in the volume unit list to see that number. 1 cubic inch = 16.387 cc. So a 350 cubic inch engine is about 5,735 cc, or 5.7 liters.

Cubic Inch Calculator

Updated Aug 25, 2026 By Jehan Wadia

Introduction

The Cubic Inch Calculator finds the volume of an object in cubic inches (in³). Pick a shape — a rectangular box, cylinder, sphere, or cone — type in the size, and get the answer right away. For a broader set of shapes, our general Volume Calculator covers more options.

You can enter sizes in millimeters, centimeters, meters, inches, feet, or yards. The tool changes them to inches for you, so there's no need to run numbers through a separate Mm To Inches Calculator or Cm To Inches Calculator first. You can also enter a box as area × height if you already know the base area from an Area Calculator.

Need more than one item? Add a quantity. Want extra material just in case? Add a waste percent. The calculator adds both to the total.

Your answer also shows up in cubic feet, cubic meters, cubic yards, liters, US gallons, and US quarts — the same conversions you'd get from our Volume Conversion Calculator. A step-by-step solution shows the math, and a chart shows how the total builds up.

This is handy for shipping box sizes, engine size, tank and container capacity, packing, 3D printing, and school homework on volume.

How to Use Our Cubic Inch Calculator

Pick a shape, type in its size, and the calculator shows the volume in cubic inches plus cubic feet, cubic meters, cubic yards, liters, gallons, and quarts.

Select a Shape: Click Rectangular Box, Cylinder, Sphere, or Cone. The input boxes change to match the shape you pick. If you only need one of these, try the dedicated Cylinder Volume Calculator, Sphere Volume Calculator, or Cone Volume Calculator.

Input Mode (box only): Choose "Dimensions (L × W × H)" if you know all three sides. Choose "Area × Height" if you already know the base area.

Length, Width, and Height: Type each side of your box and pick its unit — mm, cm, m, in, ft, or yd. You can mix units, like inches for length and feet for height. Mixed feet-and-inches measurements can be tidied up first with the Feet And Inches Calculator.

Area: In Area × Height mode, type the base area of the box and pick a square unit, such as sq in or sq ft. The Area of a Rectangle Calculator and Square Footage Calculator can help you find that number.

Radius: For a cylinder, sphere, or cone, type the radius and pick a unit. The radius is half the width across the circle — the Circle Calculator can work it out from a diameter or circumference.

Height: For a cylinder or cone, type how tall it is and pick a unit. For a cone, measure straight up from the middle of the base to the tip.

Quantity: Type how many identical items you have. The calculator multiplies the volume by this number.

Waste Allowance (%): Type a percent to add extra material for spills, cuts, or overfill. Leave it at 0 if you don't need extra. See the Percentage Calculator if you want to check the math on a buffer.

Total Volume: This fills in on its own from your sizes. You can also type a volume here and pick a unit to convert it straight to cubic inches, much like a general Unit Converter Calculator.

Decimal Places: Choose how many numbers show after the decimal point, from 0 to 4. For stricter precision rules, see the Sig Fig Calculator.

Calculate and Reset: Results update as you type, but you can click Calculate to refresh. Click Clear / Reset to start over, or click Copy to copy the cubic inch answer.

What Is a Cubic Inch?

A cubic inch (in³) is a unit of volume. It is the space inside a cube that is 1 inch long, 1 inch wide, and 1 inch tall. Volume tells you how much space an object takes up, or how much stuff can fit inside it. When you measure length in inches and multiply three of those measurements together, the answer comes out in cubic inches. If you need the outside skin instead of the inside space, use the Surface Area Calculator.

How to Find Volume in Cubic Inches

Every shape has its own volume formula. Measure each side in inches first, then use the right formula:

Rectangular box: V = length × width × height
Box from a known area: V = base area × height
Cylinder: V = π × radius² × height
Sphere: V = 4/3 × π × radius³
Cone: V = 1/3 × π × radius² × height

If your measurements are in feet, centimeters, or another unit, change them to inches before you multiply. For example, 1 foot = 12 inches, and 1 inch = 2.54 centimeters — the Inches To Cm Calculator and Metric Conversion Calculator handle those swaps.

Cubic Inch Conversions

Cubic inches can be changed into other volume units. These numbers are exact or very close:

1 cubic foot = 1,728 cubic inches — see the Cubic Feet Calculator
1 cubic yard = 46,656 cubic inches — see the Cubic Yard Calculator
1 cubic meter = about 61,024 cubic inches — see the m3 Calculator
1 liter = about 61.02 cubic inches — see the Liters To Gallons Calculator
1 US gallon = 231 cubic inches
1 US quart = 57.75 cubic inches
1 cubic inch = 16.387 cubic centimeters (cc)

Where Cubic Inches Are Used

Shipping companies use cubic inches to price boxes and figure out dimensional weight, which you can check with the Volumetric Weight Calculator, the CBM Calculator, or the Freight Density Calculator. Car and motorcycle engines are often sized in cubic inches or cc, like a 350 cubic inch V8 — the Engine Displacement Calculator and Compression Ratio Calculator work in the same units. Woodworkers, 3D printers, and machine shops use cubic inches to guess how much material a part will need, and the Board Foot Calculator covers lumber. Aquarium owners (see the Aquarium Calculator), storage planners, tank builders (try the Tank Volume Calculator or Pipe Volume Calculator), and packaging designers use it too.

Quantity and Waste Allowance

If you are making or packing more than one item, multiply the volume of one item by how many you have. A waste allowance adds a small percent on top for spills, cutting scraps, or mistakes. A 10% waste allowance means you plan for 10% more material than the math says you need, so you do not run short. Trades often build the same buffer into a Concrete Volume Calculator or Excavation Calculator estimate.

Tips for Getting It Right

Use the inside measurements when you want to know how much fits in a container, and the outside measurements when you want the space the object takes up. For circles, remember that the radius is half the diameter — using the diameter by mistake makes the answer four times too big for a cylinder; the Diameter To Circumference Calculator is useful when you only have a wrap-around measurement. Keep all your units the same before you multiply, and round only at the end with the Rounding Calculator. If you also need weight, pair your result with the Density Calculator.

Formulas used

Volume of a rectangular box

V = L \times W \times H

Volume from base area and height

V = A \times H

Volume of a cylinder

V = \pi r^2 h

Volume of a sphere

V = \frac{4}{3}\pi r^3

Volume of a cone

V = \frac{1}{3}\pi r^2 h

Total volume with quantity and waste allowance

V_{total} = V \times q \times \left(1 + \frac{w}{100}\right)

Unit conversions from cubic inches

V_{ft^3} = \frac{V_{in^3}}{1728},\quad V_{yd^3} = \frac{V_{in^3}}{46656},\quad V_{L} = \frac{V_{in^3}}{61.0237},\quad V_{gal} = \frac{V_{in^3}}{231},\quad V_{qt} = \frac{V_{in^3}}{57.75}

Frequently asked questions

Why did my quantity and waste allowance stop counting?

That happens when you type a number straight into the Total Volume box. The tool switches to manual mode and just converts the number you typed. Quantity and waste are skipped.

To turn auto mode back on, change any size in the shape section above, or click Clear / Reset.

How do I find the volume of a hollow pipe or tube?

Do the cylinder math twice and subtract:

Find the volume using the outside radius.
Find the volume using the inside radius.
Subtract the small answer from the big one.

That gives the volume of the pipe wall. If you want how much water fits inside, just use the inside radius.

Can I use this for a half sphere or dome?

Yes. Pick Sphere, type the radius, then cut the answer in half. A half sphere is exactly 50% of a full sphere.

Quick trick: set Quantity to 0.5 and the tool halves it for you.

What if my shape is not a box, cylinder, sphere, or cone?

Break it into parts. Most objects are made of simple shapes stuck together.

Example: a silo is a cylinder plus a half sphere on top. Find each part, then add them. For an L-shaped room, split it into two rectangles.

How do I measure something with a weird shape and no formula?

Use water. Fill a container with water, drop the object in, and see how much the water rises.

Every 1 cup of water pushed up is about 14.4 cubic inches. Every 1 liter is about 61 cubic inches.

Can I type fractions like 1/2 or 3 3/4?

No. The boxes only take decimals. Change your fraction first:

1/2 = 0.5
1/4 = 0.25
3/8 = 0.375
3 3/4 = 3.75

Why is my answer showing 0.00?

One of your boxes is empty or set to 0. Volume needs every measurement to be more than zero, since the numbers get multiplied together.

Check for a red warning message under each input.

For a cone, do I use the slant height or the straight height?

Use the straight height. Measure from the middle of the base straight up to the tip, not along the slanted side.

The slant side is always longer, so using it makes your volume too big.

How do I turn cubic inches into weight?

Multiply the volume by the density of the material.

Water weighs about 0.0361 pounds per cubic inch. So 100 cubic inches of water weighs about 3.6 pounds. Steel, wood, and sand all have different densities, so look yours up first.

Is cc the same as a cubic centimeter?

Yes. cc and cm³ mean the same thing. Pick cm³ / cc in the volume unit list to see that number.

1 cubic inch = 16.387 cc. So a 350 cubic inch engine is about 5,735 cc, or 5.7 liters.

Why is a cone only one third of a cylinder?

Because a cone tapers to a point, so it loses space as it goes up. If a cone and a cylinder have the same radius and the same height, the cone holds exactly 1/3 as much.

You could pour three cone-fulls into that cylinder to fill it.

I doubled the radius and the volume got way bigger. Is that right?

Yes. Radius gets multiplied by itself. In a sphere it is cubed, so doubling the radius makes the volume 8 times bigger. In a cylinder or cone the radius is squared, so doubling it makes the volume 4 times bigger.

Small radius mistakes cause big errors, so measure carefully.

What does the Volume Build-Up chart show?

It shows three bars: the volume of one item, the volume after multiplying by your quantity, and the final volume after adding waste.

It makes it easy to see how much extra material your waste percent adds.

Does changing the decimal places change my real answer?

No. The tool always does the math with the full number. Decimal places only change how much of it you see on screen.

Use 0 or 1 for quick estimates. Use 3 or 4 for small parts where tiny amounts matter.

Should shippers use cubic inches or cubic feet?

Use cubic inches for single parcels and dimensional weight, since carriers measure boxes in inches. Use cubic feet or cubic meters for pallets, containers, and truck loads.

The tool shows both at the same time, so you do not have to choose.

Can I copy the result to use somewhere else?

Yes. Click the Copy button next to the cubic inch answer. It copies the plain number, with no commas, so it pastes cleanly into a spreadsheet or form.

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