1 Ounce to Ml – Full Calculation Guide

1 ounce is equal to approximately 29.5735 milliliters (ml).

The conversion from ounce to milliliters is based on the fact that one US fluid ounce is defined as 29.5735 ml. This is a volume measurement commonly used in cooking and science to convert liquid quantities between the imperial and metric systems.

Conversion Tool


Result in ml:

Conversion Formula

The formula to convert ounces to milliliters is:

Milliliters (ml) = Ounces (oz) × 29.5735

This works because 1 US fluid ounce is exactly 29.5735 ml, a standard set by measurement authorities. So, multiplying the number of ounces by 29.5735 gives the equivalent volume in milliliters.

Example calculation:

  • Convert 2 ounces to ml:
  • 2 oz × 29.5735 = 59.147 ml

Conversion Example

  • Convert 3.5 ounces to ml:
    • Multiply 3.5 by 29.5735
    • 3.5 × 29.5735 = 103.50725 ml
    • Result: 103.5073 ml (rounded to 4 decimal places)
  • Convert 0.75 ounces to ml:
    • Multiply 0.75 by 29.5735
    • 0.75 × 29.5735 = 22.180125 ml
    • Result: 22.1801 ml
  • Convert 10 ounces to ml:
    • Multiply 10 by 29.5735
    • 10 × 29.5735 = 295.735 ml
    • Result: 295.7350 ml
  • Convert 4.2 ounces to ml:
    • Multiply 4.2 by 29.5735
    • 4.2 × 29.5735 = 124.2027 ml
    • Result: 124.2027 ml
  • Convert 7 ounces to ml:
    • Multiply 7 by 29.5735
    • 7 × 29.5735 = 207.0145 ml
    • Result: 207.0145 ml

Conversion Chart

The chart below shows ounce values from -24.0 to 26.0 and their equivalent milliliters. Negative values represent volumes below zero, which can be used theoretically in calculations involving differences or deficits.

Ounce (oz) Milliliters (ml)
-24.0 -709.7640
-20.0 -591.4700
-16.0 -473.1760
-12.0 -354.8820
-8.0 -236.5880
-4.0 -118.2940
0.0 0.0000
2.0 59.1470
4.0 118.2940
6.0 177.4410
8.0 236.5880
10.0 295.7350
12.0 354.8820
14.0 414.0290
16.0 473.1760
18.0 532.3230
20.0 591.4700
22.0 650.6170
24.0 709.7640
26.0 768.9110

Related Conversion Questions

  • How many milliliters are in 1 ounce when measuring liquids?
  • What’s the exact ml equivalent of 1 fluid ounce in recipes?
  • Is 1 ounce the same as 29.5735 milliliters everywhere?
  • How do I convert 1 oz to ml for medical dosages?
  • Why does 1 ounce equal 29.5735 ml instead of 30 ml?
  • Can I round 1 ounce to 30 ml in cooking without error?
  • What tools help converting 1 ounce to ml quickly?

Conversion Definitions

Ounce: An ounce (abbreviated oz) is a unit of volume commonly used in the United States to measure liquids. One US fluid ounce equals exactly 29.5735 milliliters. It’s part of the imperial system and often used in cooking, science, and medicine.

Milliliter (ml): A milliliter is a metric unit of volume equal to one-thousandth of a liter. It is widely used worldwide for measuring small liquid quantities, where 1 ml equals exactly 0.033814 US fluid ounces. It offers precise measurement especially in scientific fields.

Conversion FAQs

Why is 1 ounce equal to 29.5735 ml and not a round number?

The US fluid ounce is defined by law as exactly 1/128 of a US gallon, which in milliliters is 29.5735 ml. This number comes from converting gallons to liters, which results in a non-round decimal. The exactness ensures consistency in measurements across industries.

Can I use the same ounce to ml conversion for dry ingredients?

Ounce as a volume measure applies to fluids; dry ounces measure weight, so converting dry ounces to milliliters requires knowing the substance’s density. The 29.5735 ml per ounce conversion only applies to fluid ounces, not weight ounces.

Does the UK fluid ounce differ from the US fluid ounce in ml?

Yes, the UK fluid ounce is larger and equals approximately 28.4131 ml, compared to the US fluid ounce’s 29.5735 ml. This difference can cause confusion, so specifying which ounce is used is important for precise conversions.

How accurate is the conversion value 29.5735 ml per ounce?

The 29.5735 ml value is exact for the US fluid ounce, based on legal definitions. It does not approximate, so calculations using this figure are precise for volume conversions in US measurements.

Is there a quick way to estimate ounces to ml without a calculator?

Multiplying ounces by 30 gives a rough estimate, as 1 ounce is close to 30 ml. However, this rounding adds slight error, so for exact work, use 29.5735. The approximation is fine for casual cooking but not scientific uses.