Enter cubic inches or fluid ounces to convert between them using US, Imperial (UK), and US units.

In^3 to Fluid Ounces Conversion Calculator

Enter exactly 1 value to calculate the other

Assumptions Assumptions
  • Conversions are volume-to-volume only—no density or weight adjustments.
  • All units are converted through milliliters (mL) as the base: 1 in³ = 16.387064 mL.
  • Fluid-ounce standards used: US = 29.5735295625 mL, Imperial (UK) = 28.4130625 mL, US legal = 30 mL.
  • Results are idealized; container shape or fill levels are not considered.
When to Use This Calculator
  • Converting container or package volume (in³) to labeled fluid ounces for beverages or chemicals.
  • Estimating volume from dimensions for shipping, storage, or 3D-printed parts.
  • Switching between US, Imperial (UK), and US legal fluid-ounce standards.
Input Definitions
  • Cubic Inches — select in³, ft³, cm³, mL, L, or m³; all convert via mL.
  • Fluid Ounces — select US fl oz (29.5735 mL), Imperial fl oz (28.4131 mL), or US legal fl oz (30 mL).
  • Conversions — US: fl oz = in³ ÷ 1.8046875; in³ = fl oz × 1.8046875. General: fl oz = in³ × (16.387064 ÷ fl_oz_mL).

In^3 to Fluid Ounces Formula

The following formulas convert cubic inches to US fluid ounces and back; a general approach using milliliters is noted in the accordion.

\mathrm{fl~oz~(US)} = \frac{\mathrm{in}^3}{1.8046875}
\mathrm{in}^3 = 1.8046875\,\mathrm{fl~oz~(US)}
  • 1 cubic inch = 16.387064 mL
  • US fluid ounce = 29.5735295625 mL
  • Imperial (UK) fluid ounce = 28.4130625 mL
  • US legal fluid ounce = 30 mL

How do you convert in³ to fluid ounces? In US units, divide cubic inches by 1.8046875; for other standards, convert in³ to mL (×16.387064) and divide by the chosen fl oz size in mL.

How do you convert fluid ounces to in³? For US units, multiply fl oz by 1.8046875; generally, multiply fl oz by its mL value and divide by 16.387064 to get in³.

In^3 to Fluid Ounces Conversion Table

Cubic Inches to US Fluid Ounces
Cubic Inches Fluid Ounces (US)
10.554
21.108
31.662
42.216
52.771
63.325
84.433
105.541
126.649
147.758
168.866
2011.082
2413.299
2815.515
3217.732
3619.948
4022.165
4826.597
6435.463
* US customary: 1 fl oz = 1.8046875 in³ (so 1 in³ = 128/231 fl oz).

Example Problem

Convert 36.09375 in³ to US fluid ounces.

Use the US formula: fl oz = in³ ÷ 1.8046875.

fl oz = 36.09375 ÷ 1.8046875 = 20 fl oz