in3 to Fluid Ounces Conversion
A tank or part may be sized in cubic inches, while a drink is poured in ounces. Multiply in³ by 0.5541 to get US fluid ounces.
Quick answer: multiply the volume in in³ by 0.5541. For example, 1 in³ is 0.5541 fl oz, 10 in³ is 5.541 fl oz and 100 in³ is 55.411 fl oz.
The in³ to fl oz formula
One cubic inch is 128 over 231 of a US fluid ounce, which is about 0.5541 (Wikipedia: Cubic inch).
That comes from 231 cubic inches in a gallon and 128 ounces in a gallon.
Take 1 in³. Multiply by 0.5541. The answer is 0.5541 fl oz.
Take 10 in³. Multiply by 0.5541. The answer is 5.541 fl oz.
Cubic inches to US fluid ounces
A cubic inch is a cube 1 inch on each side. It is 16.387064 cm³ (Wikipedia: Cubic inch).
A US fluid ounce is 29.5735 mL (Wikipedia: Fluid ounce).
The factor 0.5541 joins the two.
How to convert in³ to fl oz step by step
- Write down the volume in in³.
- Multiply it by 0.5541.
- The answer is in fl oz.
- Check it against the chart above.
Example 1: 1 in³
- Start with 1 in³.
- 1 × 0.5541 = 0.5541.
- The volume is 0.5541 fl oz.
1 in³ = 0.5541 fl oz
Example 2: 10 in³
- Start with 10 in³.
- 10 × 0.5541 = 5.541.
- The volume is 5.541 fl oz.
10 in³ = 5.541 fl oz
Example 3: 100 in³
- Start with 100 in³.
- 100 × 0.5541 = 55.411.
- The volume is 55.411 fl oz.
100 in³ = 55.411 fl oz
A US gallon is 231 in³ and 128 US fluid ounces (Wikipedia: Gallon), so 1 in³ is 128 ÷ 231 ounce.
in³ to fl oz conversion table
| in³ | fl oz | mL |
|---|---|---|
| 1 in³ | 0.5541 fl oz | 16.387 mL |
| 5 in³ | 2.771 fl oz | 81.935 mL |
| 10 in³ | 5.541 fl oz | 163.87 mL |
| 50 in³ | 27.706 fl oz | 819.35 mL |
| 100 in³ | 55.411 fl oz | 1,638.71 mL |
| 231 in³ | 128 fl oz | 3,785.41 mL |
| 350 in³ | 193.94 fl oz | 5,735.47 mL |
| 502 in³ | 278.16 fl oz | 8,226.31 mL |
The highlighted row, 10 in³, is the default of the converter. The last column gives mL.
A quick mental shortcut for in³ to fl oz
Divide the cubic inches by 1.8 for a quick guess.
So 100 in³ is about 55.6 ounces.
What in³ measure
A cubic inch is a cube 1 inch on each side. It is 16.387064 cm³ (Wikipedia: Cubic inch).
Engine sizes in the US use it.
What fl oz measure
A US fluid ounce is 29.5735 mL (Wikipedia: Fluid ounce).
Recipes and US drink labels use it.
The gallon link
A US gallon is exactly 231 cubic inches and holds 128 fluid ounces (Wikipedia: Gallon).
So 231 in³ is exactly 128 fl oz.
US and imperial ounces
An imperial fluid ounce is 28.4131 mL (Wikipedia: Fluid ounce).
So 1 in³ is about 0.577 imperial fluid ounce (Wikipedia: Cubic inch).
Engine sizes
An engine of 502 in³ displaces about 278 US fluid ounces (Wikipedia: Cubic inch).
That is about 8.23 L.
Small parts
A part of 10 in³ holds about 5.541 fl oz.
A part of 50 in³ holds about 27.706 fl oz.
Why multiply by 0.5541
Divide 128 ounces by 231 cubic inches and you get 0.5541.
So each cubic inch holds that part of an ounce.
Going the other way
To go back, divide the ounces by 0.5541. Or multiply by 1.8047.
So 5.541 fl oz is 10 in³.
Check your answer
Your ounce number should be a bit over half the in³ number.
Divide it by 0.5541 and you should get your first number.
Quick conversion answers
| Conversion | Result |
|---|---|
| 1 in³ | 0.5541 fl oz |
| 10 in³ | 5.541 fl oz |
| 100 in³ | 55.411 fl oz |
| 231 in³ | 128 fl oz |
| 350 in³ | 193.94 fl oz |
| 502 in³ | 278.16 fl oz |
Round numbers for in³ and US fl oz
Use these round numbers to check your own answer. 50 in³ is 27.71 US fl oz, 500 in³ is 277.1 US fl oz and 5,000 in³ is 2,771 US fl oz.
Going the other way, 5 US fl oz is 9.024 in³, 50 US fl oz is 90.24 in³ and 500 US fl oz is 902.4 in³.
A round trip with in³
Say you start with 370 in³. It becomes 205 US fl oz. Divide that by the factor and you land on 370 in³ again.
Now start from 250 US fl oz instead. It becomes 451.2 in³, and multiplying by the factor returns 250 US fl oz.
Where this conversion is used
Engine and pump sizes are often given in cubic inches.
US drink cans, bottles and recipes use fluid ounces.
Common mistakes to avoid
- Mixing length and volume. A cubic unit is length times length times length.
- Using the wrong direction. Here 1 in³ is 0.5541 fl oz, so a correct answer comes out smaller than the number you start with.
- Rounding too early. The answer for 350 in³ is 193.94 fl oz. Cut it to 190 fl oz and you are off by about 2.0 percent, and the gap grows if you reuse it.
- Using the inverse factor. The factor is 0.5541. If you divide by it instead of multiplying, 10 in³ becomes 18.05 US fl oz instead of 5.541 US fl oz.
Related converters
A fuel can
A can of 462 in³ holds about 256 fl oz.
That is 2 US gallons.
A small tank
A tank of 350 in³ holds about 193.94 fl oz.
In liters that is 5.735.
Frequently asked questions
How do I convert cubic inches to fluid ounces?
Multiply the cubic inches by 0.5541.
How many fluid ounces is 1 cubic inch?
About 0.5541 US fluid ounce.
How many fluid ounces is 231 cubic inches?
Exactly 128, which is one US gallon.
How many fluid ounces is 100 cubic inches?
About 55.411 US fluid ounces.
Is the imperial ounce different?
Yes. 1 in³ is about 0.577 imperial fluid ounce.
How many mL is 1 cubic inch?
About 16.387 mL.
Sources
- Wikipedia: Cubic inch (en.wikipedia.org)
- Wikipedia: Gallon (en.wikipedia.org)
- Wikipedia: Fluid ounce (en.wikipedia.org)
