How Many mL in a Shot Glass? Stop Underestimating This Simple Fact!

When it comes to cocktails, bartenders, and spirit lovers alike, precision matters—especially when measuring ingredients. One of the most common questions isn’t what goes into a cocktail, but how much. If you’re a fan of whiskey neat, martini, or any spirit served in a shot glass, the exact volume of an imperial shot is critical to getting the strength, balance, and overall drinking experience just right.

So, how many milliliters are in a standard shot glass? The simple answer is: never underestimate this small glass—most shot glasses hold exactly 45 milliliters (ml). But here’s the depth you need to understand:

Understanding the Context

What Defines a Shot Glass?

A shot glass is traditionally defined as a drinking vessel capable of holding one “shot” of spirit—historically, sufficient to produce a standard concentration of alcohol. In the United States, and widely adopted internationally, the imperial shot glass standard holds 45 milliliters. While size may vary slightly between countries and custom designs, 45 ml is the gold standard.

Why 45 ml and Not 30 ml or 50 ml?

The 45 ml capacity balances carefully measured alcohol delivery without diluting too quickly when stirred or mixed. This volume ensures consistent dilution from ice and chilling, without overwhelming the palate. Smaller volumes like 30 ml would deliver too little alcohol, affecting taste and strength. Larger volumes, such as 50 ml, skew cocktail ratios and dilute spirits too much, diminishing their nuanced flavors.

Key Insights

Do All Shot Glasses Use Exactly 45 ml?

Technically, not all shot glasses are exactly 45 ml. Standard commercial shot glasses are uniformly graded and marked to hold 45 ml — often with a small imprint or etching indicating the measurement. Home glasses, especially repurposed ones, may vary slightly in size, so measuring is always recommended for accuracy.

Tips for Home Bartenders:

  • Measure Yours: Use a small milliliter marker or a dropper to verify if your glass reads 45 ml.
  • Stir Wisely: A 45 ml portion requires precision—over-stirring cools and dilutes, while under-stirring leaves alcohol too harsh.
  • Choose Thoughtsfully: Consider matching your glass to your spirit strength—for example, a smaller glass for a powerful whiskey shot to maintain balance.

Why This Matters Beyond Cocktails

Final Thoughts

Accurate measurement affects more than just taste—it impacts portion control, responsible drinking, and portraying cocktail craftsmanship. Whether you’re making a simple whiskey on the rocks or a complex Old Fashioned, respecting the 45 ml standard ensures your drink delivers precision and pleasure every time.

Bottom line: A standard shot glass contains 45 milliliters. This simple fact is foundational to cocktail consistency, strength, and enjoyment. Never assume—measure, stir, and savor with confidence.


Stop underestimating the power of a precise 45 ml shot glass. It’s more than a measure—it’s the backbone of great mixing.