An imperial fluid ounce is 1/160 of an imperial gallon.
Imperial fluid ounces to Femtoliters Converter — imp fl oz to fL
Convert Imperial fluid ounce (imp fl oz) to Femtoliter (fL) using the exact conversion factor (1 imperial fluid ounce = 2.841306e+13 femtoliter). See the formula, worked examples, conversion table, history, and common uses.
Imperial fluid ounces to Femtoliters converter
Converter
Volume Converter
Convert metric, US customary, imperial, cooking, dry, and industrial volume units.
Context values
Some unit families need one extra value for a physically accurate result.
Femtoliter is 1e-15 liter units.
Result = input x 2.84130625e-5 / 1e-18.
Volume uses the cubic meter as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Imperial fluid ounces to Femtoliters
Imperial fluid ounce and Femtoliter appear side by side at fuel pumps and on beverage labels, since the US measures liquids in gallons while most of the world uses liters. Imperial fluid ounce is most often used for uk/commonwealth beverage measurement in historical or specialized contexts.
Formula
femtoliters = imperial fluid ounces × 2.841306e+13
This factor comes from each unit's defined relationship to the category's base unit: 1 imperial fluid ounce equals 0.0000284130625 base units, and 1 femtoliter equals 1e-18 base units, so dividing one by the other gives the direct imperial fluid ounce-to-femtoliter factor of 2.841306e+13.
Simple example
1 imp fl oz × 2.841306e+13 = 2.841306e+13 fL
1 imperial fluid ounce = 2.841306e+13 femtoliters.
Real-world example
10 imp fl oz × 2.841306e+13 = 2.841306e+14 fL
10 imperial fluid ounces = 2.841306e+14 femtoliters.
Conversion table
| Imperial fluid ounce (imp fl oz) | Femtoliter (fL) |
|---|---|
| 1 imp fl oz | 2.841306e+13 fL |
| 5 imp fl oz | 1.420653e+14 fL |
| 10 imp fl oz | 2.841306e+14 fL |
| 25 imp fl oz | 7.103266e+14 fL |
| 50 imp fl oz | 1.420653e+15 fL |
| 100 imp fl oz | 2.841306e+15 fL |
Reverse conversion: Femtoliter to Imperial fluid ounce
2.841306e+13 fL × 3.519508e-14 = 0.999999912 imp fl oz
2.841306e+13 femtoliters = 0.999999912 imperial fluid ounces.
imperial fluid ounces = femtoliters × 3.519508e-14
For a page dedicated to this direction, see Femtoliter to Imperial fluid ounce.
Understanding the Imperial fluid ounce
Imperial fluid ounce (imp fl oz) measures volume. The imperial fluid ounce is 1/160 of an imperial gallon: exactly 28.4130625 milliliters — slightly smaller than the US fluid ounce despite the larger imperial gallon, because it divides that gallon into more parts. It is classified as a UK/imperial customary unit.
Where it's used: United Kingdom (historically; less common in current UK retail than metric units)
Imperial fluid ounce vs. US fluid ounce. Confusingly, the imperial fluid ounce (28.41 mL) is slightly smaller than the US fluid ounce (29.57 mL), even though the imperial gallon is larger overall — because the imperial gallon is divided into 160 fluid ounces rather than the US gallon's 128.
Uses of the Imperial fluid ounce today
- UK/Commonwealth beverage measurement in historical or specialized contexts
History of the Imperial fluid ounce
The imperial fluid ounce follows from Britain's 1824 imperial gallon, divided into 160 parts rather than the 128 used in the US system, producing its counterintuitively smaller size relative to the US fluid ounce.
Historical origin. Imperial fluid ounce was not the invention of a single named person; it developed through the process described above.
Understanding the Femtoliter (fL)
Femtoliter is 1e-15 liter units.
Imperial fluid ounce — sources
- UK Weights and Measures Act 1824 — Basis for the imperial fluid ounce via the imperial gallon.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many femtoliters are in 1 imperial fluid ounce?
1 imperial fluid ounce equals 2.841306e+13 femtoliters, using the exact defined conversion factor rather than an estimate.
How do I convert imperial fluid ounce to femtoliter?
Multiply the imperial fluid ounce value by 2.841306e+13. The converter above does this instantly to whatever precision you set.
How do I convert femtoliter back to imperial fluid ounce?
Use the reverse factor: 1 femtoliter equals 3.519508e-14 imperial fluid ounces. You can also use the swap control in the converter above to flip the direction instantly.
What is a imperial fluid ounce?
Imperial fluid ounce (imp fl oz) measures volume. The imperial fluid ounce is 1/160 of an imperial gallon: exactly 28.4130625 milliliters — slightly smaller than the US fluid ounce despite the larger imperial gallon, because it divides that gallon into more parts. It is classified as a UK/imperial customary unit.
What is a femtoliter?
Femtoliter (fL) is a unit of volume.
Is the imperial fluid ounce to femtoliter conversion exact?
Yes. The imperial fluid ounce is 1/160 of an imperial gallon: exactly 28.4130625 milliliters — slightly smaller than the US fluid ounce despite the larger imperial gallon, because it divides that gallon into more parts. That fixed definition is what the converter above uses, so any rounding you see is a display choice, not a limitation of the math.
What is the difference between imperial fluid ounce vs. us fluid ounce?
Confusingly, the imperial fluid ounce (28.41 mL) is slightly smaller than the US fluid ounce (29.57 mL), even though the imperial gallon is larger overall — because the imperial gallon is divided into 160 fluid ounces rather than the US gallon's 128.
Where is the imperial fluid ounce still used today?
United Kingdom (historically; less common in current UK retail than metric units)