Volume · Unit Converter

Convert Imperial Fluid Ounce to US Fluid Ounce

Convert imperial fluid ounces to us fluid ounces instantly. 1 imperial fluid ounce = 0.9607599404 us fluid ounce — use the live calculator, the exact formula, a conversion table and worked examples. Also check the US Fluid Ounce to Imperial Fluid Ounce converter for the reverse conversion.

Written by Sunith Babu L, Ph.D., Lead Engineer Reviewed by Dr. Jaya Christiyan K G, Ph.D.
Volume category 2 min read Published Last reviewed Updated

Units explained

Imperial (UK)

Imperial Fluid Ounce

What is a imperial fluid ounce?

An imperial fluid ounce is 1/160 of an imperial gallon (28.4131 mL).

Origin of the imperial fluid ounce

Defined so that ten fluid ounces make an imperial half-pint.

Where it is used

Used in UK and Commonwealth recipes and labels.

When and where it was developed

UK, 1824.

US Customary (Liquid)

US Fluid Ounce

What is a us fluid ounce?

A US fluid ounce is 1/128 of a US gallon (29.5735 mL).

Origin of the us fluid ounce

Derived from the gallon subdivision; distinct from the slightly smaller UK fluid ounce.

Where it is used

Standard for US beverage and nutrition labeling.

When and where it was developed

English customary; US since 1824.

Imperial Fluid Ounce to US Fluid Ounce conversion formula

The relationship between imperial fluid ounces and us fluid ounces:

1 fl oz = 0.9607599404 fl oz
1 fl oz = 1.0408427308 fl oz

To convert imperial fluid ounces to us fluid ounces, multiply the value in imperial fluid ounces by 0.9607599404. To reverse, multiply us fluid ounces by 1.0408427308.

How to use this converter

Type a value into the calculator. The result in us fluid ounces updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the US Fluid Ounce to Imperial Fluid Ounce converter for the reverse direction.

Step-by-step: convert imperial fluid ounces to us fluid ounces

  1. Write down the value in imperial fluid ounces (fl oz).
  2. Multiply that value by the factor 0.9607599404.
  3. The product is the equivalent value in us fluid ounces (fl oz).
  4. To reverse, multiply the us fluid ounce value by 1.0408427308.

Worked examples

Example 1 — Convert 1 fl oz to fl oz:
1 × 0.9607599404 = 0.9607599404 fl oz

Example 2 — Convert 100 fl oz to fl oz:
100 × 0.9607599404 = 96.0759940404 fl oz

Real-world example — Hair-width scale measurements

A 70-imperial fluid ounce measurement (about the diameter of a human hair) is the kind of value materials engineers regularly express in adjacent micro-scale units like us fluid ounces for direct comparison across supplier datasheets.

70 fl oz × 0.9607599404 = 67.2531958283 fl oz

Real-world example — Paper and film thicknesses

At the thickness of office paper (roughly 3 imperial fluid ounces), converting between sub-millimeter units is routine for packaging and printing buyers comparing quotes from metric and US suppliers.

3 fl oz × 0.9607599404 = 2.8822798212 fl oz

Real-world example — Plastic-film thickness alternates

A 150-imperial fluid ounce plastic film converts cleanly to us fluid ounces — useful for packaging buyers reconciling supplier datasheets across metric and US measurement systems.

150 fl oz × 0.9607599404 = 144.1139910606 fl oz

Imperial Fluid Ounce to US Fluid Ounce conversion table

Standard reference values for converting imperial fluid ounces to us fluid ounces:

Imperial Fluid Ounce [fl oz]US Fluid Ounce [fl oz]
0.010.0096075994
0.10.096075994
10.9607599404
21.9215198808
32.8822798212
43.8430397616
54.803799702
109.607599404
2019.2151988081
3028.8227982121
4038.4303976162
5048.0379970202
10096.0759940404
500480.3799702019
1000960.7599404039

Frequently asked questions

How many us fluid ounces is 1 imperial fluid ounce?
1 imperial fluid ounce equals 0.9607599404 us fluid ounce.
How do I convert imperial fluid ounces to us fluid ounces?
Multiply the value in imperial fluid ounces by 0.9607599404 to get us fluid ounces.
How do I convert us fluid ounces back to imperial fluid ounces?
Multiply the value in us fluid ounces by 1.0408427308, or use the US Fluid Ounce to Imperial Fluid Ounce converter.
How many us fluid ounces is 100 imperial fluid ounces?
100 imperial fluid ounces equals 96.0759940404 us fluid ounces, because 100 × 0.9607599404 = 96.0759940404.

Convert Imperial Fluid Ounce to other volume units

Show all Imperial Fluid Ounce conversions

Sources & references

Conversion factor (1 fl oz = 0.9607599404 fl oz) verified against the following authoritative sources:

Results are provided for general reference. Verify critical measurements against an authoritative standard.