Use the rim for its stated capacity
If a side is labeled 30 mL, a level pour to that side’s rim is 30 mL. Check whether the printed unit is mL, US fl oz, or another measure.
Jigger Measurements
Convert a cocktail pour and use the right side or marked line.
Common, not universal. Capacities vary by country, bar, and style. Test your own jigger’s accuracy.
Your measure
Exact conversion
1.5 US fl oz = 44.36 mL
All units
Common cocktail rounding
45 mL
No jigger? Exact spoon measure
3 US tbsp
On your selected jigger
Fill the 1.5 US fl oz side to its rim.
The rim matches the stated capacity in this preset. The diagram does not prove that your physical jigger is accurate.
What this jigger measures exactly
| Capability | Stated point or composition | Exact mL | Exact US fl oz |
|---|---|---|---|
| Recorded single points | |||
| Small rim | 0.75 US fl oz | 22.180147171875 mL | 0.75 US fl oz |
| Large rim | 1.5 US fl oz | 44.36029434375 mL | 1.5 US fl oz |
| Exact two-pour sums | |||
| Two-pour sum | 2 × 0.75 US fl oz small rim | 44.36029434375 mL | 1.5 US fl oz |
| Two-pour sum | 1 × 0.75 US fl oz small rim + 1 × 1.5 US fl oz large rim | 66.540441515625 mL | 2.25 US fl oz |
| Two-pour sum | 2 × 1.5 US fl oz large rim | 88.7205886875 mL | 3 US fl oz |
Enter a valid custom jigger to list its recorded capabilities.
Exact spoon equivalents: 1 US tbsp = ½ US fl oz; 1.5 US fl oz = 3 US tbsp.
Three-pour water test
How accurate is your cocktail jigger?
The stamped number alone cannot tell you. Weigh three room-temperature water pours to see both average bias and pour-to-pour consistency.
Live readout
Enter three water weights
The average, bias, and spread appear as soon as all three trials are valid.
- Average delivered
- —
- Average bias
- —
- Trial spread
- —
Reference comparison only. This kitchen test is not legal metrology, calibration, or commercial trade certification.
- Tare a dry glassPlace the receiving glass on the scale and reset it to zero.
- Fill at eye levelUse room-temperature water and stop at the stated line or rim without a dome.
- Pour, record, repeatDrain the jigger normally, record the grams, then tare and repeat twice.
What this comparison means
Accuracy is the difference between the three-pour average and the stated capacity. Consistency is the range from the lightest to the heaviest trial. A wide spread can come from fill or drain technique, so repeat the test before blaming the tool.
At room temperature, water is approximately 1 g per mL. The shaded gauge band follows the OIML R 138 transfer-measure reference: below 100 mL, ±2 mL at a marked line or 0 to +4 mL at a brim. It is context, not a universal home-jigger promise. See the method sources.
Quick jigger conversion chart
Exact US customary conversions are calculated with the published factors below. Bar rounding stays separate.
| Recipe measure | Exact metric value | Common bar shorthand | Use in converter |
|---|---|---|---|
| 0.75 US fl oz | 22.18 mL | 22.5 mL | |
| 1 US fl oz | 29.57 mL | 30 mL | |
| 1.5 US fl oz | 44.36 mL | 45 mL | |
| 2 US fl oz | 59.15 mL | 60 mL | |
| 1 US tbsp | 14.79 mL | 15 mL | |
| 1 US tsp | 4.93 mL | 5 mL |
How to read a jigger
A jigger is a measuring tool, not one universal quantity. Read the engraved unit and capacity on the tool in your hand.
Use only a real marked line
An engraved 15 mL or ¾ fl oz line can be used when it is actually present. This guide never invents intermediate lines for a preset.
Do not guess from cup height
Jiggers are tapered or curved, so half the height is not necessarily half the volume. When no reliable point exists, the tool says unavailable.
Common jigger sizes
These are useful formats to recognize, not a claim that every jigger follows one standard.
Regional note: Imperial fl oz differs from US fl oz. In the UK, licensed premises must sell gin, rum, vodka and whisky in specified metric quantities such as 25 mL or 35 mL, or their multiples; that rule does not make either size a universal cocktail jigger.
Exact conversion vs cocktail rounding
The calculator converts through milliliters at full precision. It then formats the exact answer for reading and, separately, shows a practical bar shorthand when useful.
US fl oz vs Imperial fl oz
They are different measures: 1 US fl oz is exactly 29.5735295625 mL, while 1 Imperial fl oz is 28.4130625 mL. The advanced option is explicitly labeled so a bare “oz” is never assumed.
- Exact
- 1.5 US fl oz × 29.5735295625 = 44.36029434375 mL, displayed as 44.36 mL.
- Common shorthand
- 45 mL is easy to recognize behind a bar, but it does not replace the exact conversion.
- Physical guidance
- A rim, line, or multi-pour is suggested only when it can be composed from stated capacities and recorded marks.
Jigger measurement FAQ
Short answers to the questions that most often cause a wrong pour.
How many ounces are in a jigger?
There is no universal answer. A common US measure is 1.5 US fl oz, but physical jiggers also come in 0.75/1.5, 1/1.5, 1/2 US fl oz and many metric combinations. Read the capacity marked on yours.
Is a jigger the same as a shot?
Not reliably. “Shot” sizes vary by location and venue, while a jigger is a measuring tool whose sides or lines should state specific capacities. Use the stated measurement instead of treating the words as interchangeable.
How many milliliters are in 1.5 US fluid ounces?
Exactly 44.36029434375 mL using 29.5735295625 mL per US fluid ounce, usually displayed as 44.36 mL. Bartenders often use 45 mL as a separate practical shorthand.
Why is my jigger a different size?
Jigger capacities vary by country, manufacturer, bar practice and tool style. Common metric and US customary formats coexist, and an Imperial fluid ounce is different again.
How do I measure ¾ US fluid ounce?
Use a real ¾ US fl oz line or rim when your jigger has one. The exact metric equivalent is 22.18 mL. If that mark is absent, do not assume the right level is three-quarters of the cup’s height.
What should I do if my jigger has no matching mark?
Use another marked measure or an exact multi-pour combination suggested from recorded marks. Otherwise the honest answer is that the amount is unavailable on that jigger without guessing.
How can I test a cocktail jigger’s accuracy at home?
Tare a dry receiving glass on a scale, fill the jigger to its stated line or rim with room-temperature water, pour fully, and record the weight in grams. Repeat three times. Because water is approximately 1 gram per milliliter, the average estimates delivered volume; the spread shows how repeatable the pours were. This is a kitchen check, not trade certification.
Sources and method
Conversion factors and the accuracy comparison come from primary standards sources. Common formats remain examples, never a universal definition. Last reviewed .
- NIST: US customary and metric conversions Supports the US kitchen and fluid-measure conversion context.
- NIST SP 811 Appendix B.8 Supports the exact US and Imperial fluid-ounce factors.
- NIST: density Supports the kitchen-test approximation that water is about 1 g per cubic centimeter, equivalent to 1 mL.
- OIML R 138: vessels for commercial transactions Provides the 20 °C reference conditions and comparison limits for line and brim transfer measures.
- UK Measuring Instruments Regulations 2016 guidance Confirms which capacity-serving measures are regulated and that trade use depends on the applicable conformity requirements.
- GOV.UK: specified quantities Supports the UK 25 mL and 35 mL serving-rule context.
- NIAAA: standard drink context Supports the distinction between a physical pour and a US standard-drink concept.
Conversions use milliliters as the internal base and keep full precision until display. The accuracy check treats 1 g of room-temperature water as approximately 1 mL and keeps raw trials in the browser only. Its comparison band is educational context, not certification.